A STUDY OF SELECTIONS FOR 

THE VARIATION AND INHERITANCE OF THE 

SIZE, SHAPE AND COLOR OF HENS' EGGS 



A THESIS 



PRESENTED TO THE FACULTY OF THE GRADUATE SCHOOL OF 
CORNELL UNIVERSITY 



FOR THE DEGREE O 

DOCTOR OF PHILOSOPHY 



BY 

EARL WHITNEY BENJAMIN 

1914, 1920 



A STUDY OF SELECTIONS FOR 

THE VARIATION AND INHERITANCE OF THE 

SIZE, SHAPE AND COLOR OF HENS' EGGS 



A THESIS 



PRESENTED TO THE FACULTY OF THE GRADUATE SCHOOL OF 
CORNELL UNIVERSITY 



FOR THE DEGREE OF 

DOCTOR OF PHILOSOPHY 



BY 
EARL WHITNEY BENJAMIN 



1914, 1920 



AVr ^ ^^^V.^YSA , NNMaaao.v- M 



Vo . 



3°r 






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CONTENTS 



PAGE 

Review of literature ■. 195 

Methods of investigation 198 

Size character 199 

Shape character 201 

Photographing the eggs for size and shape studies 202 

Color character 204 

Methods common to studies of all the characters 206 

Results : 208 

Inheritance studies 208 

Variability of production due to differences between the parent types 208 

Inheritance of mean egg type 215 

Relation of egg incubated to mean egg type of bird hatched 227 

Relation of eggs incubated to types of eggs produced by the respective birds 

hatched 244 

Miscellaneous studies 250 

Relationship of size and shape of eggs ; 250 

Incubation effects of egg type 252 

Relative variability of the productions of successive years 253 

Variations in types of eggs produced during successive months and years 254 

Size character 255 

Shape character 259 

Color character 262 

Variations in types of successive individual eggs 286 

Variations in types of eggs produced in different calendar months 267 

Relation between vigor of the chick and size of the egg from which it was 

hatched 269 

Relation between male and female weights for chicks of the same age 270 

Relation between size of the chick and size of the egg from which it was 

hatched 271 

Discussion of results 305 

Summary 307 

Acknowledgments 309 

Bibliography ...... 310 



191 



A STUDY OF SELECTIONS FOR THE SIZE, SHAPE, AND COLOR 

OF HENS' EGGS 



A STUDY OF SELECTIONS FOR THE SIZE, SHAPE, AND COLOR 

OF HENS' EGGS 1 

Earl W. Benjamin 

The study here reported was conducted from the spring of 1911 until 
1919, with the purpose of determining the results that may be obtained 
by selecting the breeding stock of the domestic fowl, and the eggs for 
hatching, in order to change the size, shape, and color of the eggs pro- 
duced by the offspring. There is a certain type of egg which especially 
meets the desires of the respective customers in various markets. It is 
usually not practicable to grade the eggs closely, and it becomes necessary 
to select and develop the flocks so that the proportion of eggs unsatis- 
factory to the customer may be reduced to the minimum. 

The wholesale trade of the New York City market requires the size 
and shape of the eggs to be such that the eggs are not crowded, but fit 
snugly, in the fillers of the commercial thirty-dozen cases; this means 
an egg about 2| inches long and If inches wide, and usually weighing 
from 2 to 2| ounces when fresh. Shipping only the eggs of proper size 
and shape insures less breakage, better appearance, and a resulting higher 
sale value. The New York City market has a special demand for white- 
shell eggs and will sometimes pay from eighteen to twenty cents a dozen 
more for eggs having chalk- white shells than for those varying from cream- 
tinted to brown. 

REVIEW OF LITERATURE 

The study of the external characters of eggs seems to date from a com- 
paratively recent period, and even at the present time the published 
data with respect to these characters are very meager. 

Tradition tells us (in Horace, Lib. II, st. 4) that the eggs of pullets 
are longer than those of hens, and that pullets' eggs produce a larger 
proportion of male chicks than do hens' eggs. This tradition has been 
developed until many persons believe that long eggs produce cockerels 
and round eggs produce pullets when incubated. 



1 This study completes the work reported in part in a thesis presented by the writer to Cornell Uni- 
versity in 1912 for the degree of master of science in agriculture, and continued in a thesis presented to 
Cornell University in 1914 in partial fulfillment of the requirements for the degree of doctor of philosophy. 

195 



196 Earl W. Benjamin 

The size and shape of the egg is shown by Curtis (1911a) 2 and by Surface 
(1912) to be due partly to the structure of the oviduct, which may probably 
be considered an inherited character as claimed by Newton (1893-96). 
This is in accordance with the view of Thompson (1908). This physical 
influence on the size and shape of the egg described by Thompson (1908) 
is denied by Horwood (1909), but without convincing evidence. 

The shape of the egg seems to depend on its size, according to Curtis 
(1914 a). The same author shows good correlations between the two 
dimensions of eggs, and between either of these dimensions and the weight. 
This agrees with the conclusions of Pearl and Curtis (1916). 

Curtis (1914 a) claims that the larger eggs are due to a greater relative 
deposition of egg white, while Atwood (1914) finds indications contrary 
to this. 

The size of the egg seems to be affected by the feed, according to 
Atwood (1914), and the same author shows a marked seasonal fluctuation 
in the weight of eggs laid, the weight gradually increasing from July 
to February and decreasing from March to July. This agrees with 
Curtis (1914 a) and with Fere (1898 b), who claim that the eggs are 
smaller at both the beginning and the end of the litter. Rice, Nixon, and 
Rogers (1908) and Riddle (1911) show a striking effect of the amount of 
food consumed on the number of eggs produced. According to these 
workers, both the amount of food consumed and the number of eggs pro- 
duced seem to be variable factors agreeing in their seasonal fluctuations 
with tiie size of the egg, as just noted. Curtis (1914 a) also shows a grad- 
ual reduction in size for the successive eggs in the clutch. Hadley (1919) 
shows a monthly fluctuation in the egg weight of thirty-nine White 
Plymouth Rocks which corresponds closely with the monthly numerical 
production. He finds also that the percentage increase in egg weight 
during the two modal months of increased production (April and Sep- 
tember) is positively indicative of the relative annual numerical produc- 
tion of the respective birds. 

According to Curtis (1914 a), the size of the eggs increases as the bird 
matures. Curtis states also that the variations among the eggs produced 
by individuals were not so great as the variations in the flock's production, 
and seemed to diminish as the birds matured. This agrees with the 

2 Dates in parenthesis refer to Bibliography, page 310. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 197 

results obtained in a study of the number of leaves to a whorl in 
Ceratophyllum made by Pearl, Pepper, and Hagle, 3 and in a later study 
for egg shape made by Pearl (1909). Similar variations in sparrows' 
eggs have been observed also by Pearson (1902 b). 

Stewart and Atwood (1909) report that chicks hatched from pullets' 
eggs are not so large nor so vigorous as those hatched from the eggs of 
hens two and three years old. Atwood (1914) mentions this fact as 
showing that chicks hatched from larger eggs are larger and more vigorous 
than others. It would seem that there is danger here of attributing 
any possible defect of the embryo due to the immaturity of the parent, 
to the smaller size of the egg, which also is due to the immaturity of the 
parent. The writer does not see proof that a smaller egg produces a 
smaller and weaker chick irrespective of the maturity and condition of 
the parent. 

Pearl and Curtis (1916) found that the two characters size and shape, 
as measured by weight, length, and breadth, show different degrees 
of variability, ranging from the most variable to the least variable in 
the order named. Pearl and Curtis were able also to strengthen their 
previous conclusions that the index and the weight are negatively cor- 
related. They found that dwarf or abnormal eggs do not occur more 
frequently at the beginning or at the end of the litter than at other times. 
During the ■ eight years previous to their study, 5. 15 per cent of all the 
birds kept at the Maine experiment station produced one or more dwarf 
eggs, and only 3.5 per cent of this 5.15 per cent produced more than two 
dwarf eggs. 

Abnormal types of eggs have been reported also by Von Nathusius 
(1895), Fere (1897 and 1898 b), Herrick (1899, a and b), Hargitt (1899 
and 1912), Parker (1908), Patterson (1911), Glaser (1913), Curtis (1914b), 
Chidester (1915), and Weimer (1918). Some of the abnormalities reported 
might, of course, prove to be inherited, especially such as the double 
yolks found by Glaser (1913); however, since this publication is concerned 
with normal eggs, further discussion of rare monstrosities may be omitted. 

The coloration of the shells of eggs has long been a subject of interest 
to oologists. According to Newton (1893-96), older birds usually lay 
darker-shell eggs. Newton says that some of the color is applied to the 

3 Variation and differentiation in Ceratophyllum. By Raymond Pearl, Olive M. Pepper, and Florence J. 
Hagle. Carnegie Inst. Pub. no. 58 : 1-136. 1907. 



198 Earl W. Benjamin 

shell early in its development, while some is added later — as is indicated 
by the lighter shade of an egg that has been laid prematurely, due to 
some excitement. The intensifying of the pigment with the age of the 
bird is supposed to continue until she has attained her full vigor, when 
the tint begins to decline gradually. Newton believes that except for 
individual differences the pigment is fairly constant in supply. 

Sorby (1875) found seven substances which in various mixtures are sup- 
posed to produce all eggshell colors. These substances were oorhodeine, 
oocyan, banded oocyan, yellow ooxanthine, rufous ooxanthine, a substance 
giving narrow absorption-bands in the red, and lichnoxanthine. They are 
said to be closely connected with either haemoglobin or bile pigments. 

M'Aldowie (1886) and many others have advanced theories as to the 
cause of variation in eggshell color. The general opinion seems to be that 
the color is very unstable and variations do occur frequently, and that 
general tints or colors are inherited. Horwood (1909) gives it as his 
opinion that coloration of the shells of birds' eggs has absolutely no 
connection with mendelian principles. 

According to Surface (1912), the color of eggshells is probably added 
from glands in the vagina or adjoining parts of the oviduct, and it may 
reasonably be supposed that a function of this nature would be inherited. 
Such a supposition agrees with the results of Benjamin (1912 and 1914), 
which are discussed later in this report. 

All these studies, made by various workers, show conclusively that 
with respect to many characters, including size, shape, and color, there 
is a characteristic type of egg to be accredited to each individual, and 
that some degree of inheritance has been found to exist. 

METHODS OF INVESTIGATION 

The investigation described in this memoir was begun, in the spring 
of 1911, by selecting fifty eggs for hatching for each of the follow- 
ing nine characters — three characters being grouped in each of three 
selection studies: 



Size selections 


Shape selections 


Color selections 


Large 


Long 


Chalk-white 


Medium 


Normal 


Cream-tinted 


Small 


Round 


Brown-tinted 



Study of Selections for Size, Shape, and Color of Hens' Eggs 199 

The eggs were selected from three-year-old Single Comb White Leghorn 
hens, and an effort was made to get eggs from hens that consistently laid 
the type of egg selected. The Single Comb White Leghorn breed was 
used for the study because, first, it is the commonest breed in New York 
State, and secondly, because it was desired to study these commercial 
characters of eggs by the use of commercial breeds, and the Leghorn 
predominates on commercial egg farms in the United States. The birds 
used were from the high-producing trap-nested stock of the well-established 
Cornell strain. 

size character 

The basis for selecting eggs for the size character was weight. A Harvard 
balance, equipped with a slide reading to 10 grams in tenths, was used 
early in the work, but this was later replaced by a special direct-reading 
balance (fig. 7) . 4 Exact weights were used at first, but later the weights 
were recorded in 2-gram classes and could be transferred directly for 
use in the correlation tables. Eggs weighing more than 50 grams and 
not more than 52 grams were recorded as 51 grams in weight and were 
grouped in the 50-52-gram class in the correlation tables. 

The eggs were weighed as soon as possible after they were laid, in 
order to avoid any serious losses due to evaporation. When it was neces- 
sary to hold them for some time before weighing, they were kept packed 
and in a cool, rather moist, place. After January, 1913, the eggs were 
held in an artificially cooled room at a temperature of from 32° to 40° F. 

The eggs selected for incubation each year were weighed, as well as 
all the eggs produced by any of the hens in the size-character studies. 
In the early part of the work the eggs selected for incubation were also 
measured and their length and breadth recorded. 

Just before hatching, the eggs were placed in pedigree trays. The 
trays used in 1911 were so constructed that it seemed advisable to put 
into one compartment all the eggs produced by the same hen. If more 
than one egg in a compartment hatched, it was necessary to use the average 
of all the hatched eggs in that compartment, in order to calculate the 
average type of egg which hatched. This gave a fairly accurate result 
because, as a rule, all the eggs laid by the same hen are of the same general 
type. However, as this method allowed the possibility of some error, 

4 This balance was imported by Cornelius Kahlen, New York City. 



200 



Earl W. Benjamin 





Fig. 7. specially designfd direct-reading balance for weighing eggs and 

CHICKS 



Study of Selections for Size, Shape, and Color of Hens' Eggs 201 

all incubated eggs were individually pedigreed after 1911. For the 1912 
and 1913 hatches, the compartments of the pedigree trays were made 
small enough to hold just one egg, and thus it was possible to know from 
which egg each chick hatched. In the 1914 hatch and after that time, 
the chicks were satisfactorily hatched in cloth bags. 

The day-old chicks were weighed on the same direct-reading egg scales 
as were used for the eggs. After this first weighing the chicks were 
individually weighed every four weeks on a special type of milk balance, 
by which the weights could be accurately estimated to 1/100 pound. 
When these weights were transformed to grams, as was done for some 
of the correlation tables, the calculation was made by means of the formula, 
1 pound = 453.6 grams. In the early part of the work a separate record 
was made of the vigor of the chicks. 

SHAPE CHARACTER 

The basis for selecting eggs for shape was the index figure obtained 
by dividing the greatest width of the egg by its greatest length and 




Fig. 8. specially designed ratchet micrometers held 
by woodworking clamp, for egg measurements 



multiplying the result by 100. The measurements were made by specially 
constructed ratchet micrometers with a J-inch face (fig. 8). 5 One 
micrometer was adjusted for the egg length and one for the egg width. 

5 These were manufactured by Brown & Sharpe, Providence, Rhode Island. 



202 



Earl W. Benjamin 




Fig. 9. light, and frame for holding 
eggs, as used for the shadow photo- 
graphic process 

The wire circle around the light was used early in 
the work to hold a curtain for preventing reflection 
of light from the sidewalk. The eggs are shown as 
they are placed on the film ready for exposure. 
At the right is shown the frame used for arranging 
the eggs in their proper positions 



The micrometers were held in a wood- 
working clamp to prevent error due 
to expansion which might result if 
they were warmed by being held in 
the hand of the operator. 

All eggs incubated for the shape- 
character studies, or produced by hens 
in the shape-selection studies, were 
measured and the data recorded. 

PHOTOGRAPHING THE EGGS 
FOR SIZE AND SHAPE STUDIES 

It was thought desirable to have 
some sort of graphic representations 
of the eggs selected for size and shape, 
and to compare these with represen- 
tations of the eggs that the pullets 
produced during the following year. 
Photography was the first method of 
representation considered. Since this 
was very expensive, however, the 
practice of allowing the shadows of 
the eggs to fall directly on sensitized 
photographic paper was adopted. 6 
A sheet of sensitized paper, 9 by 11 
inches in size, is slipped into the 
back of a specially constructed frame, 
where it is held securely by a wooden 
support. The sensitized paper is 
slipped in back of a sheet of stock 
film glued in the frame; this film, if 
kept clean, does not hinder the re- 
production, reflects much of the dif- 
fused light, and thus prevents the 
blurring of the shadow. 7 

The eggs are placed on the film as 
shown in figure 9, and are held in 

6 It was necessary to use high-contrast paper for this 
work, in order to obtain distinct black and white tones. 

7 This stock film is the base used for photographic 
films before the gelatinous coating is applied. It is 
transparent. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 203 




FlG. 10. PHOTOGRAPHIC STUDY OF SIZE AND SHAPE CHARACTERS 

This shows the appearance of the sensitized paper after exposure under the eggs and subsequent 
development. A record is made at the time of the exposure, identifying each egg so that, if desired, 
it may be used later in a group with all other eggs laid by the same hen 



204 Earl W. Benjamin 

place by small circles of stock film made by cutting strips of film about 
3 inches long and J inch wide and gluing the ends together. These film 
circles are transparent, thus casting no shadow, and are therefore much 
more suitable than if made of an opaque substance such as cardboard or 
metal. When the twelve eggs that are to be reproduced on each 9x11- 
inch sheet are placed on the film, they are arranged evenly by means 
of a separate frame shown in figure 9, which divides the 9x1 1-inch 
space into twelve equal parts. This frame is removed before the repro- 
duction is made. After the frame with the eggs on it is in place under 
the light, the light is turned on for an exposure varying with its power 
and its distance from the eggs. In this study, a 200-candle-power tungsten 
light, with a special parallel-ray reflector, was used, about 9 feet distant 
from the eggs, and an exposure of just one minute was required. A red 
light was used when working with the sensitized paper. 

After the exposed sheet has been developed, the eggs appear as white 
outlines on a black background (fig. 10). A key is arranged at the 
time when the exposure is made, whereby the numbers of the eggs repro- 
duced are known, so that certain eggs can be cut out of the plate at any 
time, rearranged, and photographed. 

COLOR CHARACTER 

The method of making selections for the color character, and of recording 
the colors for reference during succeeding generations of the birds, was 
a difficult one to develop. Various schemes were contemplated and 
many of these were tried. Schemes of using color tops or wheels, various 
types of colorimeters, colored photography, and so forth, were considered, 
but were discarded as being too slow, expensive, or inaccurate. It is very 
difficult to match the color of an .egg with that of any other surf ace. It was 
decided that if a system of matching colors was to be followed, in order 
to do the work rapidly the eggs must be matched to other eggs of standard 
colors. 

By a careful inspection of all eggs produced on the plant for several 
days, a graduated set of colors containing about fifty tones from chalk- 
white to dark chocolate brown was obtained. The first seventeen of 
these tones were the only ones used in the experiment. The contents of 
these eggs were blown, and the shells were numbered consecutively and 



Memoir 31 



Plate VII 







Plate VII 

KEY TO COLOR NOTATION USED FOR COLOR STUDIES OF EGGS 





Color notation number 


Equivalent in 
Repertoire de Couleurs 


'!•• 


Plate 


Ton 
( Tone ) 


1 , 


.. 1 


... .1 


2 


.11 


1 


3. . 


. 11 


.2 


4 


.. .11 


3 


5 


2 


1 


6 


10 


1 


7 


10 


2 


8 . - 


.9 


3 


9 


9 


4 


10 


. . . .312 


1 


11 


. .312 


2 


12 


67 


1 


13 


..36 


1 


14 . 


68 


1 


15 . 


68 


2 


16 


68 


3 


17 


68 


4 









200 Earl W. Benjamin 

arranged in a tray. These standard eggs were then carefully matched 
with their respective colors in Repertoire de Couleurs 8 (Plate VII). 

The color of eggshells is not permanent and will fade considerably 
if exposed to the light for any great length of time. The practice was 
tried of coating the shells with various preparations intended to preserve 
their color, but this was not successful, as all these preparations contained 
so much color in themselves that the color of the shells thus coated was 
materially changed. The method finally followed was to use, as standards, 
eggs with the natural surface. The tray of eggs was kept covered with 
a black cloth except when in use, and the standard eggs were replaced 
with others of identical color at intervals varying with the length of time 
they were used, 

A clear north light is necessary for accurate color selection, and one 
must have a trained eye in order to be sure of recording the correct color. 
The terms chalk-white, cream-tinted, and brown-tinted are used merely 
to designate the three groups of colors, in order to show the type of eggs 
selected for each lot. The color recording was done by one person early 
in the experiment and by another person later. A trial was made of 
color recording by several inexperienced persons on the same set of eggs 
for several succeeding days, and the percentage of error was found to be 
very slight. The same standard scale of colors was used thruout the 
work. The colors were numbered as shown in Plate VII, and these num- 
bers were used in the correlations and other calculations. 

METHODS COMMON TO STUDIES OF ALL THE CHARACTERS 

The chicks used in this study were reared by standard methods, in 
colony houses with the other experimental chicks on the Cornell experi- 
mental farm. Previous to 1913 the mature birds were kept in a narrow 
house divided into nine pens, one pen for each of the nine characters. 
Under these conditions the one selected male bird for each pen was allowed 
freedom in the pen. During the 1913 breeding season and after, individual 
mating coops were installed, and individual mating was followed for the 
remainder of the experiment. New houses were used for the stock after 
1913 (fig. 11). All feeding, trap-nesting, and other details of management 

8 Repertoire de couleurs. Published by La Societe Francaise des Chrysanth6rnistes and Ren6 Oberthur, 
with the collaboration of Henri Dauthenay and others. 1905. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 207 

were conducted under the supervision of the manager of the Cornell 
poultry farm and in accordance with the usual practice on that farm. 
The general plan was to save all the chicks until maturity and then 
save as many typical specimens from each group as could be satis- 
factorily housed. Usually about 120 females and 30 males were kept 
for the study of the three characters, size, shape, and color. When the 
surplus stock was culled each fall, an effort was made to save the birds 




FlG. 11. TYPE OF HOUSE USED FOR STOCK AFTER 1913 



representing the extremes of the types. If there were birds that had 
produced no chicks during the previous breeding season, these birds were 
usually culled. In cases in which nearly all the members of a certain 
family had developed only a medium quality for the character studied, 
the whole family was often culled to make room for more promising birds. 
A large proportion of cockerels and pullets were usually saved for 
the first year, and these were culled fairly closely before being used as 
breeders during the succeeding years. 



208 Earl W. Benjamin 

These methods of selection explain why so few records are actually 
available for the study of some of the characters. 

In following the method of individual mating, each male to be mated 
with any females in the pen is retained in a coop. Whenever a female 
is removed from the trap nest, the attendant finds her band number 
on a posted list and learns the band number of the male with which she 
is to be mated. Before placing her in the mating coop, however, the 
work is further checked by looking for the hen number on a tag attached 
to the coop, and also by comparing the color of her band with the color 
of the male's band. The female is then placed in the coop and removed 
at the time of the next inspection of the trap nests. Usually about twelve 
mating coops were needed in each house. 

Every egg laid by the mature birds is recorded as to either its size, 
its shape, or its color, in the same way as the original incubated eggs 
were recorded. This enables the investigator to compare the character 
of the egg incubated with the eggs which the resulting pullet produces. 
Many of the eggs from hens in the size and shape selections were also 
photographed, as previously explained. 

RESULTS 

The results of the investigation may' properly be grouped into those 
concerned with the inheritance studies and those concerned with other 
related studies, the former being dealt with first. 

INHERITANCE STUDIES 

Variability of production due to differences between the parent types 

An effort was made to determine to what extent the variability of a bird's 
production was dependent on the differences existing, for the particular 
character, in the respective dam and sire. The studies made in this regard 
are illustrated in tables 1 to 12, and a summary is given in table 13. In 
constructing these tables, the standard deviations for each of the three 
egg characters considered, for each respective year's production, were calcu- 
lated, and these were correlated with the differences existing between the 
means of the respective egg character for all the eggs produced during the 
life of the respective dam, and as calculated for the respective sire. 9 

9 The life mean for the sire was obtained by averaging his respective dam and ?ire. The character of 
the egg from which the first sires used in the study were hatched, was taken as the mean for these first sires. 

When a class is designated by one figure, that figure represents the upper limit of the class; when a clas- 
is designated by two figures, the upper figure is included in the class. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 209 

It is clear that no correlation exists for these characters. This state- 
ment, of course, has reference to the first generation only. This result 
does not show that when comparing the mean characters for the several 
offspring from a certain mating, one may not find a variability depending 
on the difference between the same characters for the respective dam 
and sire. / 

TABLE 1. Standard Deviation of Egg Size (Weight in Grams) during First Year of 
Production, Subject; Difference between Egg-Size Life Mean for Dam and for 
Sire, Relative 

Coefficient of correlation = .012 ± .052 



1.0-1.5 
1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 
5.5-6.0 
6.0-6.5 
6.5-7.0 
7.0-7.5 



1 


2 


3 


4 


5 


6 


. 7 


8 


9 


10 


11 


12 


13 14 15 16 17 18 19 20 21 22 






1 




2 










1 








2 


1 






1 




1 


2 




1 




1 




4 


2 




2 




4 


2 


1 


7 


4 


2 


2 


3 


11 


5 


3 


2 


1 


7 


2 


8 


3 


3 


2 


1 


4 1 


6 


3 


3 


4 




1 


7 


5 


2 


7 




6 


1 1 1 


3 


2 


1 
1 


1 




1 


2 
1 

1 


1 


1 


3 

1 


1 




i 1 



26 13 10 



4 

9 

33 

53 

47 

17 

3 





1 

1 



1 



4 13 16 17 13 20 5 10 9 1 1 1 1 169 



TABLE 2. Standard Deviation of Egg Size during Second Year of Production, 
Subject; Difference between Egg-Size Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = — .28 ± .08 



1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 



1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 12 13 


14 


15 


16 


17 


18 


19 














1 


1 






















2 






1 






2 


2 


2 


1 


2 


2 












1 


13 


2 


3 


1 


2 


1 


2 


2 


4 


4 


2 


1 3 














27 


2 


2 
1 


2 


1 




1 




1 


3 


1 
















10 

2 
2 







56 



210 



Earl W. Benjamin 



TABLE 3. Standard Deviation of Egg Size during Third Year of Production, 
Subject; Difference between Egg-Size Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = .13 ±.12 



1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 
5.5-6.0 



1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


13 


14 


15 


16 


17 


18 


19 
















1 


























1 




1 














1 




















1 




1 




4 




2 


1 


3 


1 


















1 


1 






1 






1 
1 

1 


2 
1 






2 














1 



13021406 4 3220000001 



1 
3 
13 
6 
4 


1 
1 



29 



TABLE 4. Standard Deviation of Egg Size during Fourth Year of Production 
Subject; Difference between Egg-Size Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = — .16 ± .20 



2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 



1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 








1 












1 


1 










1 




1 




2 




1 


1 




1 






















1 



11 



TABLE 5. Standard Deviation of Egg Shape during First Year of Production, 
Subject; Difference between Egg-Shape Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = .18 ± .08 



1.0-1.5 
1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 



.01 


.02 


.03 


.04 


.05 


.06 


.07 


.08 


.09 


.10 


.11 


.12 


.13 


.14 .15 


.16 


.17 


.18 






1 


1 




1 


1 












1 


- 








1 


4 


3 


1 




1 


1 


1 






1 


1 




1 






1 


4 


2 


2 


3 


2 


1 


1 




2 




2 




3 


1 


1 






1 


2 

1 




2 


1 


2 
1 


2 


1 
1 
1 






2 

4 


1 


1 








2 



9 6 



2 



1 

4 
16 
24 

11 
10 



70 



Study of Selections for Size, Shape, and Color of Hens' Eggs 211 

TABLE 6. Standard Deviation of Egg Shape during Second Year op Production, 
Subject; Difference between Egg-Shape Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = .14 ± .10 



.01 .02 .03 .04 .05 .06 .07 .08 .09 .10 .11 .12 .13 .14 .15 .16 .17 .18 



0.5-1.0 
1.0-1.5 
1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 





1 








1 


1 
















2 


1 


1 


1 


1 








1 








1 




1 






2 


1 


1 




1 






1 


3 




1 




1 




1 




1 






1 




1 






1 
1 










1 


1 


1 







2 



32 



TABLE 7. Standard Deviation of Egg Shape during Third Year of Production, 
Subject; Difference between Egg-Shape Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = .13 ± .18 



2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 
5.5-6.0 
6.0-6.5 
6.5-7.0 



.01 


.02 


.03 


.04 


.05 


.06 


.07 


.08 


.09 


.10 


.11 


.12 


.13 


.14 


2 
1 




1 
1 


1 
1 


1 


1 
1 

1 


' 


1 




- 






1 


1 



2 



2 
6 
2 

3 





1 

14 



TABLE 8. Standard Deviation of Egg Shape during Fourth Year of Production, 
Subject; Difference between Egg-Shape Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = .45 ± .20 



1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 



.01 


.02 


.03 


.04 


.05 


.06 


.07 


.08 


.09 


.10 


.11 


.12 


.13 


.14 


1 






2 




1 


















1 




2 






1 




1 












1 



10 



212 



Earl W. Benjamin 



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Study of Selections for Size, Shape, and Color of Hens' Eggs 213 



TABLE 10. Standard Deviation of Egg Color during Second Year of Production, 
Subject; Difference between Egg-Color Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = .43 ± .07 



0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4 



6.0 0. 



.5 8.0 8.5 9.0 9.5 



0.25-0.50 
0.50-0.75 
0.75-1.00 
1.00-1.25 
1.25-1.50 
1.50-1.75 
1.75-2.00 
2.00-2.25 
2.25-2.50 
2.50-2.75 
2.75-3.00 
3.00-3.25 
3.25-3.50 
3.50-3.75 
3.75-4.00 
4.00-4.25 
4.25-4.50 
4.50-4.75 
4.75-5.00 
5.00-5.25 
5.25-5.50 
5.50-5.75 




12 15 463654 11 1000000001 



68 



TABLE 11. Standard Deviation of Egg Color during Third Year of Production, 
Subject; Difference between Egg-Color Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = .52 ± .13 



0.50-0.75 
0.75-1.00 
1.00-1.25 
.25-1.50 
.50-1.75 
.75-2.00 
.00-2.25 
.25-2.50 
.50-2.75 
2.75-3.00 
3.00-3.25 
3.25-3.50 
3.50-3.75 
3.75-4.00 
4.00-4.25 
4.25-4.50 
4.50-4.75 
4.75-5.00 
5.00-5.25 



0.5 1.0 


1 


5 2.0 


2 


•5 


3.0 3.5 


4 


.0 


i 


.5 5.0 5.5 G.Q 6.5 7.0 7.5 8.0 8.5 9.0 9.5 


2 1 

1 

1 




1 

1 






1 




1 




1 

2 
1 
1 
1 


1 




1 






1 
1 

1 








1 



4212013160000000001 



21 



214 



Earl W. Benjamin 



TABLE 12. Standard Deviation of Egg Color during Fourth Year of Production, 
Subject; Difference between Egg-Color Life Mean for Dam and for Sire, 
Relative 

Coefficient of correlation = .55 ± .15 



1.00-1.25 
1.25-1.50 
1.50-1.75 
1.75-2.00 
2.00-2.25 
2.25-2.50 
2.50-2.75 
2.75-3.00 
3.00-3.25 
3.25-3.50 
3.50-3.75 
3.75-4.00 



0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 




1 4 


5 







1 


1 


1 


1 







1 


1 

















1 


1 







1 
, 


1 





110000304000000000 



10 



TABLE 13. Summary of Correlations between Standard Deviation of Egg Char- 
acters during Each of the First Four Years of Production, Subject, and 
Difference between Respective Life Means for Dam and for Sire, Relative 



Selection 


Year of production 


Coefficient 

of 
correlation 


r 

eT 


Number 
of indi- 
viduals 


Size 


First 


.012±.052 
-.28 ±.08 

.13 ±12 
-.16 ±.20 


0.23 
3.50 
1.08 
0.80 


169 




Second 


56 




Third 


29 




Fourth 


11 








Shape 


First 


.18 ±.08 
.14 ±10 
.13 ±.18 
.45 ±.20 


2 25 
1.40 
0.72 
2.25 


70 




Second '. 


32 




Third 


14 




Fourth 


10 








Color 


First 


.13 ±05 
.43 ±.07 
.52 ±.13 
.55 ±.15 


2.60 
6.14 
4.00 
3.67 


174 




Second 


68 




Third 


21 




Fourth 


10 









Study of Selections for Size, Shape, and Color of Hens' Eggs 215 

Inheritance of mean egg type 

The correlations shown in tables 14 to 22 and summarized in tables 23 
md 24 indicate a distinct positive relation between the mean type of 
either or both parents and the production of the offspring. In table 23 

r 

it is seen that =- for the sire ranges from 3 to 18; for the dam, from 4 
Er 

to 22; and for the average of both parents, from 8 to 39. In table 24 it 
is seen that =r ranges, for size, from 4 to 10; for shape, from 3 to 8; and 
for color, from 18 to 39. 

TABLE 14. Total Average Size (Weight in Grams) of Production of the Off- 
spring, Subject; Size Record for Sire, Relative 

Coefficient of correlation = .36 ± .04 



30 1 1 

38 

40 

42 

44 

46 11 

18 3 2 2 1111 1 12 

50 4 3 2 2 3 12 17 

52 2 2 3 5 5 6 111 2 28 

51 23 247231 121 5 33 
■63 2 122 52413 121 6 32 

53 1 1 122 11 311 9 23 
00 11113 4 11 
62 1 ' 112 5 
61 113 5 
66 11114 
88 
70 
72 
74 1 1 

13 5 13 3 13 15 24 9 10 4 1 8 8 5 33 173 



210 



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COCO'rJlTtl'^Tji-rjiiOiOiOi-OiOCOOCOCOCOt^t>-t-^ 



Study of Selections for Size, Shape, and Color of Hens' Eggs 217 



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Study of Selections for Size, Shape, and Color of Hens' Eggs 219 



TABLE 18. Total Average Shape of Production of the Offspring, Subject; Shape 

Record for Dam, Relative 

Coefficient of correlation = .47 ± .06 



54 
56 

58 
60 
62 
64 
66 
68 
70 
72 
74 
76 
78 
80 



58 59 60 61 62 63 64 


65 


66 


67 


68 


69 


70 


71 


72 


73 


74 


75 


76 


77 


78 


79 80 








1 


























1 
































1 1 








1 
2 


2 

2 




1 

1 


















1 






3 


1 


2 




5 


3 






1 






1 




1 






3 
1 
3 
1 


2 


2 
1 
1 




7 

o 

o 


o 

1 

1 






1 


3 
1 

1 
1 

1 


2 
1 


1 

o 


1 
1 



102000200 12 6 10 18 







2 



1 
1 




6 
5 
17 
23 
9 
8 
4 
2 

76 



TABLE 19. Total Average Shape of Production of the Offspring, Subject; Average 
Shape Record for Sire and Dam, Relative 

Coefficient of correlation = .49 ± .06 



54 
56 
58 
60 
62 
64 
66 
68 
70 
72 
74 
76 
78 
80 



54 55 56 57 58 59 60 61 62 63 64 


65 


66 


67 


68 


69 


70 


71 


72 


73 


74 75 












1 












1 






















1 


1 


1 


2 


1 














1 1 






2 




1 












1 




1 




1 


5 


4 


3 




1 


1 


1 


1 


3 


2 


2 


4 


5 


3 


1 


1 










1 




2 


1 


3 


1 




1 


1 










3 
2 


1 
2 


3 




2 





10000 



o : 3 



4 18 13 12 



1 1 



1 
1 





6 
5 
17 
23 
9 
8 
4 
2 



76 



220 



Earl W. Benjamin 



TABLE 20. Total Average Color of Production of the Offspring, Subject; Color 

Record for Sire, Relative 

Coefficient of correlation = .53 ± .03 



1.0-1.5 
1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 
5.5-6.0 
6.0-6.5 
6.5-7.0 
7.0-7.5 
7.5-8.0 
8.0-8.5 
8.5-9.0 



2.0 


2.5 


3.0 


3.5 


4.0 


4.5 


5.0 


5.5 


6.0 


6.5 


7 


.0 


7.5 


8 





8.5 






3 






2 


3 






• 


1 














9 




5 






5 


1 


2 






2 














15 




9 


1 




6 


5 


1 






11 














33 


2 


10 


2 


1 


8 


7 








8 














38 


1 


5 
2 
i 

2 


2 
3 
1 




1 
3 

2 


6 

11 

5 

7 


1 

3 
1 
2 




2 


1 
2 
2 
1 














19 
24 
12 
12 


1 


1 
1 

1 




1 


1 

1 


1 

1 


1 
1 


1 


1 
3 
2 


1 
1 

3 

4 
2 




6 


3 

13 

1 






2 


6 
3 
2 
8 
26 
8 

1 



40 



29 47 



12 



39 



17 



216 



TABLE 21. Total Average Color of Production of the Offspring, Subject; Color 

Record for Dam, Relative 

Coefficient of correlation = .67 =b .03 





1.5 


2.0 


2.5 


3.0 


3.5 


4.0 


4.5 


5.0 


5.5 6 


6.5 


7.0 


7.5 


8.0 




1.0-1.5 






6 


3 




















9 


1.5-2.0 






8 


2 


1 


2 








2 








15 


2.0-2.5 




5 


10 


7 


3 


2 


1 


3 


1 








1 


33 


2.5-3.0 


1 


3 


7 


9 


4 


2 


4 


1 


3 


4 








38 


3.0-3.5 


2 


1 


2 


4 




2 




2 


2 1 


2 






1 


19 


3.5-4.0 






4 


7 


5 


2 


2 


2 


2 










24 


4.0-4.5 




1 




6 


1 


1 


1 




1 


1 








12 


4.5-5.0 




1 


1 


3 


2 




1 


2 


1 


1 








12 


5.0-5.5 






1 




1 


1 






1 


2 








6 


5.5-6.0 






1 








1 






1 








3 


6.0-6.5 
















1 


1 










2 


6.5-7.0 


















1 


1 


4 


2 




8 


7.0-7.5 






1 








1 








8 


11 


5 


26 


7.5-8.0 






1 


1 


1 












2 


1 


2 


8 


8.0-8.5 































8.5-9.0 








1 




















1 



11 42 43 18 12 



11 



11 



13 



14 



14 



14 



216 



Study of Selections for Size, Shape, and Color of Hens' Eggs 221 



TABLE 22. Total Average Color op Production of the Offspring, Subject; Average 
Color Record for Sire and Dam, Relative 

Coefficient of correlation = .79 ± .02 



1.0-1.5 

1.5-2.0 
2.0-2.5 
2.5-3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 
5.5-6.0 
6.0-6.5 
6.5-7.0 
7.0-7.5 
7.5-8.0 
8.0-8.5 
8.5-9.0 



2.5 


3.0 


3.5 


4.0 


4.5 


5.0 


5.5 


6.0 


6.5 


7.0 


7.5 




3 


2 


1 


2 


1 














9 


3 


4 


1 


2 


4 




1 










15 


7 


2 


7 


1 


10 


4 




1 


1 






33 


6 


2 


6 


8 


13 


2 






1 






38 


1 


3 
3 


2 
3 


7 
11 


3 

7 


1 




2 








19 
24 


1 


1 




4 


4 


2 












12 






4 


5 
2 


1 
3 


1 


' 1 




1 






12 

6 




1 






1 

1 








1 
1 
3 


1 

1 


3 


3 
2 

8 










1 




1 




2 


5 


17 


26 


1 






2 
1 










2 


2 


1 


8 

1 



22 



18 



24 



45 



49 



10 



12 



21 



216 



TABLE 23. Summary of Correlations between Total Average Characters of 
Production of the Offspring, Subject, and Average Characters of Parents, 
Relative 



Correlated parentage 


Character studied 


Coefficient 

of 
correlation 


r 
Er 


Number 
of indi- 
viduals 


Sire 


Size 

Shape 


.36±.04 

.21±.07 

53±.03 


9 
3 

18 


173 
76 




Color 


216 








Dam 


Size 


22±05 
.47±.06 
.67±.03 


4 

8 

22 


173 




Shape 


76 


i 


Color 


216 








Average of sire and dam 


Size 


.42d=04 
.49±.06 
.79±.02 


10 

8 

39 


173 




Shape 


76 




Color 


216 









222 



Earl W. Benjamin 



TABLE 24. Summary Given in Table 23 Arranged According to Characters 



Character 


Correlated parentage 


Coefficient 

of 
correlation 


r 
Er 


Number 
of indi- 
viduals 


Size 


Sire 


.36±04 

22±.05 

.42±.04 


9 

4 

10 


173 




Dam 


173 




Sire and dam 


173 








Shape 


Sire 


21db.07 

.47±.06 
.49±06 


3 

8 
8 


76 




Dam 


76 




Sire and dam 


76 








Color 


Sire 


.53±.03 
.67=b.03 
.79±.02 


18 
22 
39 


216 




Dam 


216 




Sire and dam 


216 









All of these correlations are significant, especially since they arise 
from a random population. From the results of this study, it would 
appear that the quality of either the male or the female parent will affect 
the type of egg to be produced by the offspring, with the female having 
slightly greater influence. A certain character is of much greater influence 
if possessed by both individuals than if possessed by either one alone. 
This does not agree with some results obtained by Pearl (1912, and 1915 a 
and b) in dealing with quantity of production, and it does not show quite 
the conditions found by Goodale (1918), who also worked with the quantity 
factor; it does agree fairly closely, however, with the general opinion 
prevailing among poultrymen. 

The results for the whole experiment relative to the mean character 
of the progeny in relation to the respective characters of the sire and 
the dam, are charted in figures 12 to 17. References to large, small, 
round, long, brown, or white parents or progeny relate to the quality of the 
eggs produced by those birds, not to the size, shape, or color of the birds. 
The terms large and small refer, respectively, to means of the sizes of 
eggs produced during the birds' lifetime, of 56 grams or more, and of 
less than 56 grams; the terms round and long refer to means of the index 
figures of the eggs produced during the birds' lifetime, of 72 or more, and 
of less than 72, respectively; and the terms brown and white refer to means 
of the color of eggs produced during the birds' lifetime, of 3 or higher, 



Study of Selections for Size, Shape, and Color of Hens' Eggs 223 



and of lower than 3, respectively. The exact means for the various 
groups shown in figures 12 to 14 are given in table 25: 

TABLE 25. Mean Characters of Birds Available for Use in Calculating Data 

for Figures 12 to 14 



Character 
type 


Mating 


Mean 

character 

for sire 


Mean 
character 
for dam 


Mean 
character 

for 
progeny 


Size 


Large sire and small dam 


59.6 
51.7 
60.3 
51.7 


51.5 
60.6 
59.6 
51.7 


54 3 




Small sire and large dam , 


53 9 




Large sire and large dam 


57.2 




Small sire and small dam 


51.6 








Shape 


Round sire and long dam 


73.0 
67.0 
73.0 
65.4 


69.3 
75.4 
76.0 
69.1 


71 5 




Long sire and round dam 


72.5 




Round sire and round dam 


75.0 




Long sire and long dam 


71.0 




Brown sire and white dam 




Color 


4.81 
2.11 
4.56 
2.34 


2.34 
4.78 
4.55 
2.19 


3.00 




White sire and brown dam 


3.27 




Brown sire and brown dam 


3.75 




White sire and white dam 


2.60 









Weight 
(grams) 




Large Small Prog- 
sire dam eny 
(25) (49) 



Small Large Prog- 
sire dam eny 
(18) (81) 



Large Large Prog- 
sire dam eny 
(23) -(41) 



Small Small Prog- 
sire dam eny 
(17) (39) 



Fig. 12. mean size characters of sires, dams, and progeny in all matings 

The figures in parenthesis designate the numbers of birds available for the respective calculations 



224 



Earl W. Benjamin 



Shape 
index . 

80 

75 

70 

65 

60 

55 

50 

45 

40 

35 

30 

25 

20 

15 

10 
5 




1 1 


1 1 


1 M M 


H 


u 


-% ■ 


... 




1 <* 

j hi m i t 


| 


1 fj 


g / ! 


,'.'- 


' 1 


if 


§ 



Round Long Prog- 
sire dam eny 
(3) (9) 



Long Round Prog- 
sire dam eny 
(10) (26) 



Round Round Prog- 
sire dam eny 
(1) (2) 



Long Long Prog- 
sire dam eny 
(16) (46) 



Fig. 13. mean shape characters of sires, dams, and progeny in all matings 

The figures in parenthesis designate the numbers of birds available for the respective calculations 



Color 



51 

4.8- 

4.5- 

4.2- 

3.9- 

3.6- 

3.3- 

3 0- 




































































































































































































































































































^^H 






































































2 7 


















































2.4- 
2.1- 
1.8- 
1.5- 
1.2- 
0.9- 
0.6- 
0.3 

















































































































































































































































































Brown White Prog- 
sire dam eny 
(27) (70) 



White Brown Prog- 
sire dam eny 
(12) (30) 



Brown Prown Prog- 
sire dam eny 
(33) (70) 



White White Prog- 
sire dam eny 
(27) (29) 



Fig. 14. mean color characters of sires, dams, and progeny in all matings 

The figures in parenthesis designate the numbers of birds available for the respective calculations 

It is seen in figures 12 to 14 that in every instance in which one 
extreme character has been mated with another, the progeny have dis- 



Study of Selections for Size, Shape, and Color of Hens' Eggs 225 

played a character between the two. In most instances in which the sire 
and the dam were both of the same extreme character, the progeny dis- 
played a character nearer to normal than either of the parents. In the 
case of small size, however, this tendency was reversed, and the 
character for the progeny from two small parents was of a still smaller 
type. In this case it is probable that the effect of the size of body was 
to limit the size of the eggs (Benjamin, 1914). 

The relative effect of the sire and the dam is shown clearly in figures 
15 to 17. In figure 15 it is seen that small size is predominant over large 
size. The sire will transmit small size to the progeny much more strongly 
than large size. In the instance in which both parents are large, only 
58.6 per cent of the progeny possess the "large" character; but when 

P) **) f) 

V 65.6%) V 58.6% J \e/.9<% I 

Large sire Small sire large sire Small sr e 

Small dam Large dam Large dam Small dam 

Fig. 15. relation of progeny size characters to sire and dam 

The white area in each case designates the proportion of progeny showing the same character as that of 




the sire 



both parents are small, 81.9 per cent of the progeny possess the "small" 
character. The two parents appear here to have about equally strong 
influence in transmitting the "small" character. The predominance of 
the small size may be due to the additional physiological factors involved 
by the size of the dam's body restricting the size of egg which can possibly 
be produced, without regard to any inherited tendencies. A hen with 
a large body can produce a small egg, but a hen with a small body cannot 
so readily produce a large egg. 

The question of the inheritance of egg shape may not be entirely free 
from the physiological complications involved in the study of egg size. 
This opinion is borne out by figure 16. The dam seems to have nearly 
60 per cent of the influence on the progeny. The fact that the two long 
parents have a somewhat higher percentage of the progeny following 
their type than do the two round parents, would lead to the theory that 



226 



Earl W. Benjamin 



the length character is somewhat predominant over the width; other- 
wise one would expect to find more than 50 per cent of round progeny 
when both sire and dam are round. 

Both the size and the shape of the egg seem to be about equally trans- 
mitted to the progeny by the dams and by the sires. These two factors 




Round sire 
Long dam 



Long sire 
Round dam 



Round sire 
Round dam 



Long sire 
Long dam 



Fig. 16. relation of progeny shape characters to sire and dam 

The white area in each case designates the proportion of progeny showing the same character as that of 

the sire 



appear, however, to be independent, as is shown by an entire lack of 
correlation between them (Benjamin, 1912). Such a condition as is 
found here is the reverse of what might be expected if the results obtained 
by other workers (Pearl and Curtis, 1916) on Barred Plymouth Rocks 
were borne out with the strain of White Leghorns used in these experi- 







Brown sire 
White dam 



White sire 
Brown dam 



Brown sire 
Brown dam 



White sire 
White dam 



Fig. 17. relation of progeny color characters to sire and dam 

The white area in each case designates the proportion of progeny showing the same character as that of 

the sire 

ments. Pearl and Curtis found the index figure and the weight of eggs 
to be negatively correlated. 

The study of the color inheritance (fig. 17) shows about equal influences 
of sire and dam. When both parents are of the l 'white" character, 
they seem to be able to transmit their character more definitely than when 



Study of Selections for Size, Shape, and Color of Hens' Eggs 227 

both are of the "brown" character, but this difference is not great. 
Neither color and neither parent seem to have a predominance. 

These results are an accumulation of data from six different years, 
with all the variations in conditions that must always occur. Hence 
the facts shown can apparently be accepted as giving undoubted evidence 
of the inheritance of the characters in question. 

Relation of egg incubated to mean egg type of bird hatched 

The correlations shown in tables 26 to 49, and summarized in tables 
50 and 51, show a general relationship between the particular type of 

egg incubated and the type of egg produced by the chick hatched, both for 

r 
the separate years of the bird's production and for its life mean. 10 =- 

is much less significant for these studies than for the studies of the relation 
existing between the mean productions of parents and progeny. Apparently 
the particular type of egg incubated has some effect on the type of egg 
which the offspring will produce, but not so much effect as the mean 
production of the hen which laid that incubated egg. 

In this study the coefficient of correlation for the size character, as 
shown in table 50, is of greater significance than that for the other char- 
acters, as is the case in all of the work here reported. The shape character 
shows a fair degree of correlation. 

The color character exhibits a peculiar condition. The correlations with 
the pullets' eggs incubated, for the first and second years, are insignifi- 
cant; the third-year correlation is based on too few individuals to be of 
much value; and the life-mean correlation shows a distinct negative 
coefficient. This condition is probably due to the great irregularity 
that exists in the coloration of successive eggs laid by most individuals. 
Sufficient proof is not at hand to warrant the conclusion that a negative 
correlation actually exists for this character, but it is believed that such 
a negative or insignificant correlation may be expected, due to the irregu- 
larity of the material. 

10 The terms pullet and hen, as used in this memoir, refer to female birds during their first season of 
production and during their later seasons of production, respectively. 



228 



Earl W. Benjamin 



TABLE 26. Mean Size (Weight in Grams) of First Year's Production of Birds, 
Subject; Size of Pullets' Eggs from Which Respective Birds Were Hatched, 
Relative 

Coefficient of correlation = .40 ± .063 



46 
48 
50 
52 
54 
56 
58 
60 
62 
64 
66 



45 


47 


49 


51 


53 


55 


57 


59 


61 


63 


65 






1 


















1 


2 


2 




2 




2 










1 


1 


5 




2 


1 




1 








1 


1 


1 
1 


1 


4 
5 


1 


3 


2 

1 


1 










1 


3 


2 


3 


4 


3 






1 






2 


1 
1 


4 

1 


1 
2 
1 
1 


1 
1 


1 
1 


2 
1 







13 



20 10 



11 



1 

9 

11 

11 

11 

17 

12 

4 

3 

1 

1 

81 



TABLE 27. Mean Size of Second Year's Production of Birds, Subject; Size of Pul- 
lets' Eggs from Which Respective Birds Were Hatched, Relative 



47 



Coefficient of correlation = .37 zb .103 
49 51 53 55 57 59 



61 



50 


1 






1 










2 


52 




1 














1 


54 


1 


1 








2 




1 


5 


56 




1 




3 






1 


1 


7 


58 






1 




2 




1 


1 


6 


60 




1 




2 


1 




1 




6 


62 










1 








2 


64 








1 






1 




3 


66 





















68 





















70 














1 




1 



33 



Study of Selections for Size, Shape, and Color of Hens' Eggs 229 



TABLE 28. Mean Size of Third Year's Production of Birds, Subject; Size of Pul- 
lets' Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .30 ± .131 



47 49 



51 



53 55 



57 



59 61 



50 




1 












1 


52 


1 


1 






1 






3 


54 






1 




2 




1 


5 


56 


1 




1 






1 




3 


58 






2 


2 








4 


60 




1 






2 






3 


62 






1 










1 


64 










1 






1 


66 



















68 



















70 



















72 
74 












1 






1 



22 



TABLE 29. Mean Size of Fourth Year's Production of Birds, Subject; Size of Pul- 
lets' Eggs from Which Respective Bjrds Were Hatched, Relative 

Coefficient of correlation = .50 ± .191 



50 
52 
54 
56 
58 
60 
62 
64 
66 
68 



47 


49 


51 


53 


55 


57 


59 


1 


1 




1 

1 




1 
1 


1 



2 1 



230 



Earl W. Benjamin 



TABLE 30. Mean Size op Life Production of Birds, Subject; Size of Pullets' Eggs 
from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation - .37 =fc .065 



46 
48 
50 
52 
54 
56 
58 
60 
62 
64 
66 
68 
70 
72 
74 



45 


47 


49 


51 


53 


55 


57 


59 - 


61 


63 


65 






1 


















1 


1 


2 




2 




2 










1 


1 


3 




1 


1 




1 








1 




2 


1 


3 


1 




1 










2 


1 




7 




3 


1 


1 










2 


2 


2 


1 


3 


3 


1 




1 






1 


2 


4 


3 




1 


2 










1 


1 


1 


1 

2 
1 


1 
1 


1 

1 


1 







13 



20 10 



10 



9 

15 

15 

13 

6 

2 

3 









1 

81 



TABLE 31. Mean Size of First Year's Production of Birds, Subject; Size of Hens' 
Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .31 ± .065 



36 
38 
40 
42 
44 
46 
48 
50 
52 
54 
56 
58 
60 
62 
64 
66 



45 


47 


49 


51 


53 


55 


57 


59 


61 


63 


65 


67 


69 














1 














1 




1 
1 
3 


1 
2 


1 
1 




1 

3 




















3 


2 


o 
o 


2 


5 




1 


1 








2 




3 


2 


1 


4 


2 


2 




1 


1 


2 


1 






2 

1 

1 


2 
3 


1 

2 
1 


2 
2 
1 

1 


4 

1 




1 
2 

1 
1 


1 


1 

1 


1 
1 



13 11 8 17 12 



1 



1 
2 
4 
8 
17 
20 
15 
9 
5 
1 
4 
1 

SS 



Study of Selections for Size, Shape, and Color of Hens' Eggs 231 



TABLE 32. Mean Size of Second Year's Production of Birds, Subject; Size of Hens' 
Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .46 ± .099 



50 
52 
54 
56 
58 
60 
62 
64 
66 
68 
70 



45 


47 


49 


51 


53 


55 


57 


59 


61 


63 


65 


67 




1 


1 


1 


2 


1 


1 












1 






1 
2 


1 


1 
2 


1 




1 




1 




1 


1 




1 


1 


1 








3 

1 


1 


1 




2 
2 
3 
6 
3 
1 
4 

2 
1 

29 



TABLE 33. Mean Size of Third Year's Production of Birds, Subject; Size of Hens' 
Eggs from Which Respective Birds Were Hatched, Relative 



52 
54 
56 
58 
60 
62 
64 
66 



45 47 



Coefficient of correlation = .65 ± .123 
49 51 53 55 57 59 61 



63 



65 







2 




1 


1 
2 

1 




1 


2 



1 
1 




1 
1 



10 



282 



Earl W. Benjamin 



TABLE 34. Mean Size of Life Production of Birds, Subject; Size of Hens' Eggs 
from Which Respective Birds Were Hatched, Relative 



36 
38 
40 
42 
44 
46 
48 
50 
52 
54 
56 
58 
60 
62 
64 
66 



Coefficient of correlation = .34 ± .063 
45 47 49 51 53 55 57 59 61 63 65 67 69 



71 73 75 















1 


















1 


2 




2 




















1 




2 


3 






4 


















1 




1 


2 


3 


3 


5 




1 


1 










1 




1 


3 


1 


4 


2 


1 






1 


2 








1 


4 


1 




2 


4 


1 




1 


1 


1 




1 






1 
1 


1 

2 


3 

2 


1 
1 


1 
1 
1 


1 


1 
2 

1 


1 


1 


1 


1 



5 11 11 9 16 14 



1 



1 





1 

4 
10 
17 

16 
16 

8 
6 
5 

6 

90 



TABLE 35. Mean Shape of Fir^t Year's Production of Birds, Subject; Shape of 
Pullets' Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .39 ± .106 



64 
63 
68 
70 

72 
74 
76 
78 
80 



68 


69 


70 


71 


72 


73 


74 


75 


76 


77 


78 


79 


80 






1 






















1 


1 

2 




1 
1 


1 
3 


1 
2 


1 
2 
1 
1 


2 


1 
1 


1 

2 

1 


1 




1 



1 

2 
3 
4 
10 
6 
1 
1 
1 

29 



Study of Selections for Size, Shape, and Color of Hens' Eggs 233 



TABLE 36. Mean Shape of Second Year's Production of Birds, Subject; Shape of 
Pullets' Eggs from Which Respective Birds Were Hatched, Relative 



Coefficient of correlation = .23 ± .192 
70 71 72 73 74 75 76 



77 




4 
4 

2 

1 

11 



TABLE 37. Mean Shape of Life Production of Birds, Subject; Shape of Pullets' 
Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .43 ± .102 




234 



Earl W. Benjamin 



TABLE 38. Mean Shape of First Year's Production of Birds, Subject; Shape of 
Hens' Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .34 ± .033 
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 77+ 



54 
56 

58 
60 
62 
64 
66 
68 
70 
72 
74 
76 
78 
80 



I 




2 




1 










1 


1 


1 


1 


2 


1 


1 








1 


1 


1 






2 


1 


3 


2 




1 










2 



1 





1 










2 








1 




2 


2 




1 


2 
2 


1 
1 


1 

1 
1 


1 



1 






5 
7 
6 
17 
8 
4 
3 
1 

52 



TABLE 39. Mean Shape of Second Year's Production of Birds, Subject; Shape of 
Hens' Eggs from Which Respective Birds Were Hatched, Relative 



67 68 



Coefficient of correlation = .47 ± .101 
69 70 71 72 73 74 75 



76 




Study of Selections for Size, Shape, and Color of Hens' Eggs 235 



TABLE 40 Mean Shape of Third Year's Production of Birds, Subject; Shape of 
Hens' Eggs from Which Respective Birds Were Hatched, Relative 
Coefficient of correlation = . 52 ± . 142 



54 
56 
58 
60 
62 
64 
66 
68 
70 
72 
74 



69 


70 


71 


72 


1 








1 










1 




1 



73 



74 75 76 77 





1 





























1 




1 


1 


4 


1 


2 


1 


3 



12 



TABLE 41 Mean Shape of Life Production of Birds, Subject; Shape of Hens' Eggs 

from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .31 ± .084 



54 
56 

58 
60 
62 
64 
66 
68 
70 
72 
74 
76 
78 
80 



61 or 



less 62 63 64 65 66 67 68 69 70 ' 71 72 73 74 75 76 77 77 + 







1 














1 




1 




1 














1 




1 


1 








1 


1 




1 




2 


2 




3 


1 


1 




2 


1 
1 


2 
1 


1 
3 

1 


1 
1 


1 
1 

2 



1 





1 




1 






2 


3 
1 




1 


1 


1 



110 110323346737461 



1 






1 

5 
3 

12 
16 
6 
5 
3 
1 

53 



236 



Earl W. Benjamin 



TABLE 42. Mean Color of First Year's Production of Birds, Subject; Color 
Pullets' Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = — .12 ± .07 



OF 



6 



1.0-1.5 


1 


2 


3 


1 




1 
7 


1.5-2.0 


1 


7 


3 


2 


1 


14 


2.0-2.5 


7 


8 


3 






18 


2.5-3.0 


4 


12 


2 


4 


1 


23 


3.0-3.5 


6 


3 


1 


3 


1 


14 


3.5-4.0 


1 


1 


1 






3 


4.0-4.5 


1 


1 


2 






4 


4.5-5.0 


3 


3 


1 




1 


8 


5.0-5.5 


1 




2 






3 


5.5-6.0 


2 




2 






4 


6.0-6.5 















6.5-7.0 















7.0-7.5 


1 


1 








2 



28 38 20 



10 



1 100 



TABLE 43. Mean Color of Second Year's Production of Birds, Subject; Color of 
Pullets' Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .002 ± .105 



1.0- 1.5 


1.5- 2.0 


2.0- 2.5 


2.5- 3.0 


3.0- 3.5 


3.5- 4.0 


4.0- 4.5 


4.5- 5.0 


5.0- 5.5 


5.5- 6.0 


6.0- 6.5 


6.5- 7.0 


7.0- 7.5 


7.5- 8.0 


8.0- 8.5 


8.5- 9.0 


9.0- 9.5 


9.5-10.0 


10.0-10.5 



1 


2 


3 


4 


5 


6 


7 






1 










1 


2 












1 


4 












2 


2 


1 


1 






1 


3 


2 


1 


1 








2 


1 
3 


1 
1 


1 








2 


1 












1 




2 










1 


1 













1 

3 
5 
7 
7 
3 
5 
1 
3 

3 
1 
1 






1 



13 16 



41 



Study of Selections for Size, Shape, and Color of Hens' Eggs 237 



TABLE 44. Mean Color of Third Year's Production of Birds, Subject; Color of 
Pullets' Eggs from Which Respective Birds were Hatched, Relative 

Coefficient of correlation = .57 db .15 



1.5-2.0 


1 






1 


2.0-2.5 











2.5-3.0 




2 




2 


3.0-3.5 




1 


1 


2 


3.5-4.0 


1 


1 




2 


4.0-4.5 




1 




1 


4.5-5.0 











5.0-5.5 











5.5-6.0 






1 


1 



TABLE 45. Mean Color of Life Production of Birds, Subject; Color of Pullets 
Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = — ,26 =b .06 



6 



1.0-1.5 


1 


2 


2 






5 


1.5-2.0 


1 


6 


2 




2 


11 


2.0-2.5 


5 


6 


3 




1 


15 


2.5-3.0 


5 


11 


2 


5 


1 


24 


3.0-3.5 


5 


4 


1 


2 


1 


13 


3.5-4.0 


2 


4 


3 






9 


4.0-4.5 


1 


1 


2 


1 




5 


4.5-5.0 


3 


3 


1 




1 


8 


5.0-5.5 


2 




2 






4 


5.5-6.0 


2 




1 






3 


6.0-6.5 















6.5-7.0 















7.0-7.5 


1 


1 








2 


7.5-8.0 






1 






1 



28 38 



20 



100 



238 



Earl W. Benjamin 



TABLE 46. Mean Color op First Year's Production of Birds, Subject; Color of 
Hens' Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .20 ± .08 





1 


2 


3 


4 


5 


6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 


1.0-1.5 






1 








1.5-2.0 


2 


2 


4 


1 






2.0-2.5 


1 


3 


3 


2 




1 


2.5-3.0 


5 


3 


3 


3 




2 


3.0-3.5 


1 


2 


1 


1 


1 


1 


3.5-4.0 


3 


2 






1 




4.0-4.5 


1 


1 


2 


2 


1 




4.5-5.0 


1 








1 




5.0-5.5 




1 


2 






1 


5.5-6.0 












1 


6.0-6.5 














6.5-7.0 


1 












7.0-7.5 














7.5-8.0 






1 








8.0-8.5 














8.5-9.0 




1 











15 15 17 9 4 400000000100001 



1 
9 
10 
16 
7 
6 
7 
2 
4 
1 

1 

1 


1 

66 



TABLE 47. Mean Color of Second Year's Production of Birds, Subject; Color of 
Hens' Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .31 ± .10 
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 



1.0-1.5 


1 








1.5-2.0 




1 


1 




2.0-2.5 


1 


2 


3 


1 1 


2.5-3.0 








1 


3.0-3.5 






2 


1 


3.5-4.0 


2 








4.0-4.5 








1 1 


4.5-5.0 




1 


1 


1 


5.0-5.5 






1 


1 


5.5-6.0 








1 


6.0-6.5 










6.5-7.0 










7.0-7.5 










7.5-8.0 










8.0-8.5 










8.5-9.0 


1 









5484230000000 1 01 



1 
2 
8 
1 
3 
2 
2 
4 
o 

1 

1 



1 

28 



Study of Selections for Size, Shape, and Color of Hens' Eggs 239 

TABLE 48. Mean Color of Third Year's Production of Birds, Subject; Color of 
Hens' Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .17 =k .20 





12 3 4 


5 6 / 


7 8 9 1 


11 12 13 1 


4 15 16 


17 18 19 20 


1.0-1.5 


1 












1.5-2.0 


1 












2.0-2.5 




1 










2.5-3.0 


1 












3.0-3.5 














3.5-4.0 


1 












4.0-4.5 


1 








1 


1 


4.5-5.0 


1 












5.0-5.5 




1 










5.5-6.0 














6.0-6.5 














6.5-7.0 














7.0-7.5 


1 













1141110000000 1 01 



1 
1 
1 
1 



1 

3 

1 
1 




1 
11 



TABLE 49. Mean Color of Life Production of Birds, Subject; Color of Hens' Eggs 
from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .28 ± .08 

12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 



1.0-1.5 
1.5-2.0 
2.0-2.5 
2.5-.3.0 
3.0-3.5 
3.5-4.0 
4.0-4.5 
4.5-5.0 
5.0-5.5 
5.5-6.0 
6.0-6.5 
6.5-7.0 
7.0-7.5 
7.5-8.0 
8.0-8.5 
8.5-9.0 



1 












1 1 3 


1 










2 4 4 


1 










5 3 3 


2 




2 






1 2 . 


2 




2 






3 2 


1 


1 








1 1 2 


2 


1 








1 1 1 




2 








3 








1 


1 


1 1 












1 













15 15 18 9440000000 1 01 



1 

6 
11 
15 
7 
7 
7 
5 
3 

2 


2 

1 

67 



240 



Earl W. Benjamin 



TABLE 50. Summary of Correlations between Character Means for Production 
for Separate Years and for Life, Subject, and Characters for Parent Eggs 
Incubated from Pullets or from Hens, Relative 



Character 


Year of 
production 
(means for) 


Pullets' eggs incubated 


Hens' eggs incubated 


Coefficient 

of 
correlation 


r 
Er~ 


Number 
of indi- 
viduals 


Coefficient 

of 
correlation 


r 
Er 


Number 
of indi- 
viduals 


Size 


First 

Second 


.40 ±.033 
.37 ±.103 
.30 ±.131 
.50 ±.191 
.37 ±.065 


6.3 
3.6 
2.3 
2.6 
5.7 


81 
33 

22 

7 
81 


.31±.065 
.46±.099 
.65±.123 


4.8 
4.6 
5.3 

5'4 


88 
29 




Third 


10 




Fourth 






Life 


.34±.083 


90 








Shape 


First 

Second 

Third 


.39 ±.106 
.23 ±.192 


3.7 
1.2 


29 
11 

29 


.34±.083 
.47±.101 
.52±142 
.31±.084 


4.1 
4.7 
3.7 
3.7 


52 
27 

12 




Life 


.43 ±.102 


4.2 


53 


Color 


First 


-.12 ±.07 
.002± . 105 
.57 ±.15 

-.23 ±.03 


1.7 
0.02 
3.8 
4.3 


100 

41 

9 

100 


.20±.08 
.31±.10 
.17±20 
.28±.08 


2.5 
3.1 
0.8 
3.5 


66 




Second 


28 




Third 


11 




Life 


67 









TABLE 51. Summary Of — - from Table 50 

Er 



Year of 
production 



First 



Second 



Third 



Life 



Character 



Size . . 
Shape 
Color. 

Size . . 
Shape 
Color. 

Size. . 
Shape 
Color . 

Size . . 
Shape 
Color . 



r 

Er 



Pullets' eggs 
incubated 



6.3 
3.7 

1.7 



3.6 
1.2 
0.02 



Hens' eggs 
incubated 



5.7 

4 2 
4 3 



4.8 

4.1 
2.5 



4.6 
4 7 
3.1 



o 6 
3.7 
0.8 



5.4 
3 7 
3.5 



Study of Selections for Size, Shape, and Color of Hens' Eggs 241 

The summary in table 5 1 groups the figures for the factor of significance, 

r 

-j=r> according to years and life means. There is a more significant cor- 
relation between the life mean of the offspring production and the type 
of parent egg incubated, than between the production of any of the separate 
years and the incubated egg. This means that the egg incubated affects 
the mean type of egg produced during the whole life of the bird hatched, 
to a greater extent than it affects the pullet-year production or the pro- 
duction of any other single year. 

There is a strong correlation, as shown in tables 52 to 54, when a study 
is made of the relationship between the individual eggs incubated and all 



TABLE 52. Size (Weight in Grams) of Eggs Laid by Birds, Subject; Size of 
Eggs from Which Respective Birds Were Hatched, Relative 

Coefficient of correlation = .458 ± .007 
46 48 50 52 54 5G 58 60 62 64 66 68 70 72 74 



28-30 
30-32 
32-34 
34-36 
36-38 
38-40 
40-42 
42-44 
44-46 
46-48 
48-50 
50-52 
52-54 
54-56 
56-58 
58-60 
60-62 
62-64 
64-66 
66-68 
68-70 
70-72 
72-74 
74-76 





1 








1 














1 
























3 


1 






















4 


6 






2 
















3 


6 
















1 






2 


8 


1 


5 










1 


5 






10 


8 


3 


27 




2 


2 




1 








41 


32 


11 


63 


3 


3 


9 






5 






68 


45 


23 


82 


28 


12 


30 




3 


11 






77 


108 


32 


89 


32 


30 


76 


4 


5 


44 


1 




45 


155 


39 


41 


45 


70 


124 


8 


11 


76 






26 


129 


65 


29 


79 


98 


110 


29 


25 


137 


8 




15 


69 


79 


25 


143 


120 


91 


51 


27 


153 


12 


1 


3 


42 


45 


24 


129 


87 


65 


1 104 


35 


157 


1 


1 


1 


24 


28 


17 


75 


50 


59 


74 


59 


94 


4 


1 




6 


33 


13 


28 


36 


38 


1 38 


46 


79 


2 




1 


6 


10 


2 


15 


28 


35 


30 


116 


31 










6 


1 


5 


17 


22 


17 


85 


16 
















1 


4 


1 


49 


1 




1 






1 




1 


1 
1 


1 
1 




19 

13 

3 

2 


1 







1 
1 

4 
12 
10 

22 

53 

167 

302 

498 

614 

735 

786 

694 

486 

320 

274 

169 

57 

22 

14 

5 

3 



303 646 376 418 585 557 667 



2 358 500 811 28 



5,250 



the individual eggs produced by the respective birds hatched. The 

r 
factor t=t equals, for size, shape, and color, respectively, 65, 20, and 16. 

This is significant and suggests the same relative degrees of inheritance 
as are found in other studies in this investigation. 



242 



Earl W. Benjamin 



The comparable coefficients of variability, calculated on the basis of 
unit classes, for the eggs used in compiling tables 52 to 54 are: for size 
(table 52), 20 per cent; for shape (table 53), 10 per cent; for color (table 54), 
74 per cent. The greater irregularity in the color of eggs as compared 



TABLE 53. 



54- 56 

56- 58 



60 
62 
64 
66 



58- 
60- 
62- 
64- 
66- 68 
68- 70 
70-72 
72- 74 
74- 76 
76- 78 
78- 80 
80- 82 
82- 84 
84- 86 
86- 88 
88- 90 
90- 92 
92- 94 
94- 96 
96- 98 
98-100 



Shape of Eggs Laid by Birds, Subject; Shape of Eggs from Which 
Respective Birds Were Hatched, Relative 

Coefficient of correlation = .204 ± .01 



1 



2 

14 

46 

127 

326 

624 

840 

961 

707 

307 

71 

17 

11 

3 

1 



2 

1 

2 



2 



64 66 


68 


70 


72 


74 


76 


78 80 














1 










1 


1 








6 


1 


3 


2 


2 


2 




21 


1 


7 


7 


8 






65 


6 


24 


16 


16 






146 


17 


71 


58 


34 






132 


38 


222 


152 


80 




1 


143 


44 


310 


193 


146 






97 


80 


397 


175 


211 






39 


43 


355 


122 


148 






21 


13 


175 


59 


29 






5 


4 


48 


4 


10 






1 




9 


3 


4 






1 




9 
3 

1 

1 




1 
1 






1 














2 




1 


1 





1 680 247 1,637 796 701 1 4,065 



with the other characters undoubtedly accounts for the results in this 
one correlation with the pullets' eggs incubated. The coefficients of 
correlation for the study of the mean production with the hens' eggs are 
positive for all characters and years. The color correlation is about as 
significant as the shape correlation. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 243 

TABLE 54. Color of Eggs Laid by Birds, Subject; Color of Eggs from Which 
Respective Birds Were Hatched, Relative 

Coefficient of correlation = ,145 ± .009 



1 
2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 



6 



8 



143 


238 


40 


182 


175 


117 


10 


33 


396 


298 


168 


188 


206 


107 


26 


16 


215 


174 


173 


183 


227 


56 


42 


31 


68 


119 


137 


110 


173 


32 


33 


14 


27 


71 


62 


85 


86 


24 


12 


22 


15 


44 


47 


47 


41 


8 


12 


21 


7 


18 


28 


31 


21 


7 


1 


6 


12 


14 


26 


44 


17 


2 


1 


14 


1 


5 


18 


15 


26 




2 


16 


4 


5 


26 


20 


19 


3 


2 


7 


1 


2 


21 


19 


30 


7 


3 


8 


1 




19 


5 


10 


2 






1 


6 
1 


8 
16 


9 


11 
6 


2 




2 


1 




2 




1 
















1 









938 

1,405 

1,101 

686 

389 

235 

119 

130 

83 

86 

91 

37 

39 

23 

3 

1 

1 



892 995 791 938 1,050 367 144 190 5,367 



Grams _ ^ 




December January February March April 

Fig. 18. variation of size (weight in grams) of successive eggs laid during 

early pullet production 

The squares blocked in black indicate the days on which eggs were laid by the respective pullets 



244 



Earl W. Benjamin 



Relation of eggs incubated to types of eggs produced by the respective birds 

hatched 

Some further features of the relationship existing between the types of 
eggs incubated and the egg types produced by the respective birds hatched, 
are shown in figures 18 to 25. These figures represent only a small part 
of the available material resulting from the study, and are used here 
merely to show typical conditions. 

Grams 




Weeks 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 

Fig. 19. variation of size (weight in grams), by weekly averages, of eggs pro- 
duced BY DAM FOR TWO YEARS AND BY PROGENY DURING EARLY PULLET PRODUCTION 

The heavy horizontal line in each division represents the character of the parent egg incubated; the 
heavy curve represents the production of the chick hatched; the light curve represents the production 
of the progeny of the chick. The dotted lines indicate that no eggs were produced during the periods 
which they cover 

Pullets 8882F and 8939F, illustrated in figure 18, are from small eggs, 
but pullet 8872F is from a large egg. It is evident that the tendencj' 
is for a pullet to produce eggs of the same size as the egg from which 
she was hatched. Sometimes small eggs are obtained from hens that 



Itudy of Selections for Size, Shape, and Color of Hens' Eggs 245 




^IG. 20. SHADOW PHOTOGRAPHIC RECORD OF RELATION BETWEEN SIZE OF EGG INCUBATED 
AND SIZE OF EGGS PRODUCED BY THE RESULTANT CHICK 

Each row of progeny production shows twelve eggs, which were selected at regular intervals during 
le respective year's production. All eggs were photographed each year, but only twelve eggs for each 
ear could be represented in this group 



246 



Earl W. Benjamin 



ordinarily lay large eggs, and vice versa; this probably accounts for the low 
correlation in studies of mixed flocks, while the study of separate matings 
shows more definite results. The heavy curve for fine 3916F in figure 19 
represents the record for the bird whose early pullet daily record is shown 
as 8882F in figure 18. 

The photographic record, figure 20, shows the relative sizes of eggs 
produced by line 8224F, one of the largest fines, and by line 3916F, one 
of the smallest lines. The difficulty of observing the fine differences in 
size, except by careful measurements, is seen from this figure. Under 
line 3916F is shown another record of the production of 8882F. 




January February March April 

Fig. 21. variation of shape of successive eggs laid during early pullet 

production 

The squares blocked in black indicate the days on which eggs were laid by the respective pullets 



In figures 21 and 22 are shown the daity and weekly fluctuations of 
shape. A photographic record of two of the first -year inheritance results 
for the shape character is shown in figure 23. Both of the lines shown in 
figure 23 are shown also in figure 22. Neither the shape nor the size of 



Study of Selections for Size, Shape, and Color of Hens' Eggs 247 



eggs has a large coefficient of variability, and this fact is reflected in the 
curves and in the photographic record. 



Shape 
index 




Weeks 6 11 16 21 26 . 31 36 41 46 51 56 61 66 .71 76 81 86 91 96 101 



Pig. 22. variation of shape, by weekly averages, of eggs produced by dam for 
two years and by progeny during early pullet production 

The heavy horizontal line in each division represents the character of the parent egg incubated; the 
leavy curve represents the production of the chick hatched; the light curve represents the production 
jf the progeny of the chick. The dotted lines indicate that no eggs were produced during the periods which 
;hey cover 



The color character has a much higher coefficient of variability, as may 
i be observed from figures 24 and 25. The pullets included in figure 24 
were all of the brown-egg type, but in figure 25 both brown-egg and white- 
3gg types are shown. In these figures there seems to be a tendency for 
ithe type of egg produced by the original pullet hatched, and her later 
oft spring, to resemble the original egg incubated. The writer can explain 
the negative or practically zero correlation for the color character in the 



248 



Earl W. Benjamin 




Fig. 23. shadow photographic record of relation between shape of egg incu- 
bated AND SHAPE OF EGGS PRODUCED BY THE RESULTANT CHICK 

Each row of progeny production shows twelve eggs, which were selected at regular intervals during the 
respective year's production. All eggs were photographed each year, but only twelve eggs for each year 
could be represented in this group 



Study of Selections for Size, Shape, and Color of Hens' Eggs 249 

data previously reviewed, only by the high coefficient of variability and 
the probability that many abnormal eggs are incubated instead of the 
normal type for the respective dam. 



in 


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December 



January- 



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Fig. 24. variation of color of successive eggs-laid during early pullet 

production 

The squares blocked in black indicate the days on which eggs were laid by the respective pullets 






250 



Earl W. Benjamin 



Color 




■ ■■■■■■■■ ■■■■■■■■■■ IBl'M ■■■■'. ■■■■.' . ^■•-. ■■■■■■■■■■ ■■■■■ ■■■■••■■■■ 

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L TIT T I 1 I I _T _ ___ . ! i : . ■ : . . . : i . : i - ' . _ 










Weeks 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 



Fig. 25. variation of color, by weekly averages, of eggs produced by dam for 
two years and by progeny during early pullet production 

The heavy horizontal line in each division represents the character of the parent egg incubated; the 
heavy curve represents the production of the chick hatched; the light curve represents the production of 
the progeny of the chick. The dotted lines indicate that no eggs were produced during the periods which 
they cover 

MISCELLANEOUS STUDIES 

A few studies were made in addition to those relating solely to the degree 
of inheritance existing for the size, shape, and color characteristics. These 
are discussed in the following pages. 

Relationship of size and shape of eggs 

A study was ma'de of a mixed assortment of pullets' eggs (table 55), 
which showed practically a zero correlation. This does not agree with 
results reported by Pearl and Curtis (1916). Some individuals, and some 
different strains and breeds, may possess characteristics the reverse of those 
of the strain of Single Comb White Leghorns used in these experiments. 






Study of Selections for Size, Shape, and Color of Hens' Eggs 251 



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COCOCOCOCOTj<TtlTtl-rJ<TtliOiOirjiO'OCOCOCOCO l ©t> <I J 



252 Earl W. Benjamin 

Incubation effects of egg type 
In the 1911 hatch the incubation records of the eggs were studied in rela- 
tion to the egg type. These studies, as shown in tables 56 and 57, do not 
indicate any definite relationship between egg type and incubation record. 

TABLE 56. A Study of Egg Types and Incubation Records 


Type of eggs 
incubated 


Per cent 
of infertile 

eggs 
for each 
character 


Per cent 
of 

total 
infertile 

eggs 


Per cent 

of 

dead germs 

for each 

character 


Per cent 

of 

total 

dead 

germs 


Per cent 

hatched 

for each 

character 


Per cent 

of 

total 

chicks 

hatched 


Large 


6 
4 
8 

6 

8 

16 

4 
4 



11 

7 

14 

11 
14 
29 

7 
7 



54 
68 
40 

54 
54 

58 

54 
70 

58 


10.5 
13 

8 

10.5 
10.5 
11 

10.5 

14 

11 


40 
23 
52 

40 
38 
23 

42 
23 
42 


12 

8 

15 

12 
11 

8 

13 

8 

13 


Medium 

Small 


Long 


Normal 


Round 


Brown-tinted 

Cream-tinted 

Chalk-white 


TABLE 57. Relation of Size of Eggs Incubated to Their Incubation Records 


Weight of eggs 
incubated 

(grams) 


Infertile eggs 


Dead germs 


Chicks hatched 


Total 
number 
of eggs 


Number 


Per 

cent 


Number 


Per 

cent 


Number 


Per 
cent 


42-44 


2 

1 
1 
1 
3 
2 
2 
4 
3 
5 
3 
1 





22 

4 

7 

4 

4 

3 

3 

7 

7 

14 

13 

20 


4 

6 

8 

7 

14 

43 

37 

40 

30 

22 

23 

14 

3 

1 



1 


44 
60 
30 
44 
55 
63 
60 
61 
57 
50 
62 
58 
60 
100 


3 

4 

18 

8 

10 

21 

23 

24 

19 

19 

9 

7 

1 








33 
40 
67 
50 
40 
30 
37 
33 
33 
43 
24 
29 
20 


9 


44-46 


10 


46-48 


27 


48-50 


16 


50-52 


25 


52-54 


70 


54-56 


62 


56-58 


66 


58-60 


53 


60-62 


44 


62-64 


37 


64-66 

66-68 


24 
5 


68-70 


1 


70-72 . 





72-74 


100 


1 






Total 


28 




256 




lfifi 




450 










1 







Study of Selections for Size, Shape, and Color of Hens' Eggs 253 

In table 57 the eggs incubated were grouped according to size and 
incubation results, in order to see whether any effect on the incubation 
record exists. No definite effect is shown by the data available here. 

Relative variability of the productions of successive years 

The standard deviation for all the eggs produced each year by each 
of the available hens was studied, in order to learn whether there is an 
approach to a definite egg type for the eggs produced by a hen as she 
becomes older. The data from this study are collected in figures 26 and 



<S/'ze-se/ecr/<X7 Jb/rcfs 
3.40 T 



3.20 



S/Ta/^Tse/ec/zo/? x£//k6-_ «. Co/or- &e/ee//b/7 ^>//c<r__.__ . 



3.00 



2.80 



2.60 



2.40 



2.20 




Year 1st 



Fig. 28. standard deviations for successive years, grouped as to character 

The figures in parenthesis designate the number of birds available for the respective calculations 

27. In figure 26 the studies are segregated into the three character 
groups. The reduction of the number of birds available for study in 
the fifth and sixth years makes the data for these years of doubtful value, 
altho the number of eggs used for each bird is in each case sufficient to 
make the standard deviation of real value. 



254 



Earl W. Benjamin 



In figure 27 the data for the three characters are combined both by a 
weighted and by an ordinary average. This figure does not show the 
definite tendency toward a reduction in the variability which is claimed 
by some other investigators (Pearl, 1909), altho if the data for the 
fifth and sixth years could be given as much value in this discussion as 
is given to the data for the first four years, a straight line fitted to the 
curve would show a distinct reduction in the standard deviation. The 
unweighted averages are shown in figure 27 because if it can be considered 
that the standard deviations calculated for the respective character 

dis&nzge of ihree characters, i>re/ghfed 



"finr n/jmhti/' r>f h/'nr/.^ tzach /v^ar- 




L/mre/ghfea' oi/ercrge^^ 


2 80-, 


•~ - " *" ~ '7 
















2 60- 














~" •» _ 


^^Z^^ 


— «». 






9 4ft- 


"~ "*j" "~~ — 


^Z^ 00 ^^^ 




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^•v^ 


^ 


2 20- 










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11) 




9 nn- 




















\\ 


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\\ 












\ \ 


1 60- 










\ ^ 












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1 40- 
























1.20. 













Year 1st _ 2d 3d 4th 5th 6th 

Fig. 27. standard deviations of all characters for successive years 

The figures in parenthesis designate the number of birds available for the respective calculations 

groups are based on a sufficient number of individuals to be trustworthy, 
none of these characters should be handicapped in the average if it hap- 
pened that a less number of individuals were available for that particular 
character than for the others. This is especially true since this is a 
comparison of standard deviations based on a grouping according to classes 
of widely different values. 

Variations in types of eggs produced during successive months and years 

The study of the variations of eggs produced dming successive months 
and years was carried on with birds that began to lay in different months, 
as noted in table 58. 

The time of beginning to lay is varied enough in the data used here to 
nearly eliminate seasonal effects. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 25 5 



TABLE 58. Percentage of Each Year's Flock Beginning to Lay in the Respective 
Months from November to June, Inclusive 



Month when 
laying began 



Percentage of year's flock that began laying in respective months 



First 
year of 

pro- 
duction 



Second 
year of 

pro- 
duction 



Third 
year of 

pro- 
duction 



Fourth 
year of 

pro- 
duction 



Fifth 
year of 

pro- 
duction 



Sixth 
year of 

pro- 
duction 



November . 
December . 
January. . 
February. 
March .... 

April 

May 

June 



0.3 
21.7 
29.6 
28.2 
11.2 

9.0 



1.1 

8.6 

28.0 

28.4 

22.6 

9.7 

1.1 

0.5 



5.6 



6.2 
28.4 
46.9 
18.5 



2.6 

2.6 

43.6 

48.6 
2.6 



5.6 
33.3 

49.9 

5.6 



20.0 
80.0 



Size character 

The variations in the mean size of. the eggs produced during the successive 
months by the size-selection birds are shown in figures 28 to 31. These 
curves are made up by calculating the mean for the first month's pro- 
duction of the first year, the second month's production of the first year, 
and so on for the succeeding months and years for each hen used, 
and then finding the mean for all available hens at each period. Data 
for eleven months of each year were available for a sufficient number 
of birds to make the figures reasonably reliable. 

The size of the eggs produced by pullets increases fairly regularly 
during the year, but no real increase in the size of the eggs produced during 
the later years of production can be observed. It may seem that this 
statement is disproved by figure 30, but a glance at figure 28 shows that 
the size of the first year's production increases so rapidly that it causes 
the mean size to increase slightly. 

All seasonal effects are eliminated in these studies, the birds baing 
arranged in accordance with the month when they began laying each 
year, irrespective of the particular month which that happened to be. It 
would seem that the wide fluctuations after the ninth month in figure 28, 
and after the seventh month in figure 29, may be due to the fact that too 
few birds were available for study; but an apparent tendency for the size 
of the egg to increase rapidly near the end of the laying season is observed. 



256 



Earl W. Benjamin 



/fear? for f/rsf 
Grams t/eorj prodc/cf-^ 



A/ea/7 for secorrc? fo 
s/lrfh years proc/c/cf m 




Month 1st 2d 3d 4th 5th 6th 7th 8th 9th 10th 11th 

Fig. 28. monthly variation in size of eggs produced during a period of six 

YEARS 

The figures in parenthesis designate the number of birds available for the respective calculations 



Second years T/?/rd years fbvr/f> years f~//7ri years S/xifc years 

— pnoa'ucf — proc^acf — • — •— pro&tscf* - prolucr ,, , . 



Grams p roc /t/c/' 




Month 1st 2d 3d 4th 5th 6th 7th 8th 9th 10th 11th 

Fig. 29. monthly variation in size of eggs produced during a period of six 

YEARS 

The figures in parenthesis designate the number of birds available for the respective calculations 



Study of Selections for Size, Shape, and Color of Hens' Eggs 257 



It should be noted that the individuals whose data are used for the 
later months of the year, shown in figures 28, 29, and 30, are those that 
laid during the longest period and were very likely to be the highest pro- 
ducers (Rice, 1914). This would indicate an agreement with Curtis 

jB/r</s w/Y/7 /ife mean of 
^■S or /ess 56-60_^ . , 




74- 

70 

66 

62 

58 

54 

50 

46 



I ,-«, (45; (4-3) elSfc'o— ••!" 

T — 1 T CI^^V^F 



~^sj; 




Month 1st 



11th 



Fig. 30. monthly variation in size of eggs produced during a period of six 

YEARS 

The figures in parenthesis designate the number of birds available for the respective calculations 

The curve representing the birds having a life mean of 45 or less does not lie entirely within that range 

because the whole six-years data on which the life mean is based is not available in monthly means for 

this chart 

(1914 a) and Hadley (1919) to the effect that the conditions causing the 
production of a great many eggs will also cause the production of large 
eggs. In order to see whether the results shown in figures 28, 29, and 30 
were due to the selection of high-producing birds from the low producers, 
as suggested above, figure 31 was constructed for five individuals which 



258 



Earl W. Benjamin 



began laying in December and continued laying for about the same period 
as the others (until August). No material difference can be observed 
between the types of curves shown in figure 31, and those shown in 
figures 28, 29, and 30. There seems, then, to be no marked error due 
to the possible selection of birds in the study of the random flocks, and 
it is probable that the curves for heavy producers are not materially 
different from those for lower producers. 

-> J * y 

f/rsf t/earj- Seconc/ </&ors 7??/rc/ t/&c?rs fai/ff/7 ysorr /vf//7 t/ecrrs 
prxxJucf /p/rx/ucr/<^^^*^^> p/vx/c/cf— * «. • ^^rvcfuc?— _ M —^DfTOc/ucf. • • • • 

Grams 







March 



April 



Aug. 



Fig. 31. mean monthly size records for five normal individuals for a period 

of five years 



After the great increase in the size of the eggs from the first to the se*cond 
year, there seems to be a gradual decrease in the size of the eggs produced 
during successive years. This last statement does not agree with the 
results of Curtis (1914 a). 

No decreased size of the eggs produced at the beginning and at the end 
of the litter is observed, as claimed by Fere (1898 b) and Curtis (1914 a), 
and there is no appreciable difference in the variations for the birds laying 
large, medium, and small eggs (fig. 30). 



Study of Selections for Size, Shape, and Color of Hens' Eggs 259 

Shape character 

In order to study the relative monthly and yearly shapes of eggs pro- 
duced, the data for shape selection were prepared for figures 32 to 35 in 
the same way that the data for size selection were prepared for figures 
28 to 31. There is shown a tendency for the eggs produced each year, 
even in the pullet year, to have a gradually increasing index until the 
fifth or sixth month of production, after which this index gradually decreases 
until the season's production ceases (fig. 32). 



Index joroc/uef 



/procfuc/ «— __ 








73 - 
72 - 
71 

70 - 
69 * 
68 - 
67 - 










£J> _ 


(52) 
















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Month 1st 



2d 



3d 



4th 



5th 



6th 



7th 



8th 



9th 



10th 11th 



Fig. 32. monthly variation in shape of eggs produced during a period of six 

YEARS 

The figures in parenthesis designate the number of birds available for the respective calculations 

According to figure 32, the eggs produced during the pullet year are 
of practically the same shape as those produced in later years. The 
difference may be considered insignificant. The reader should be warned 
against erroneous interpretation of the fifth and sixth years' production 
shown in figure 33, because of the very few individuals available for study 
for those years. 

As indicated in figure 34, there seems to be no radical difference between 
the variation of the groupings according to the life means of the birds. 
Where slight differences are shown, these may usually be considered as 
being due to an insufficient number of individuals available for study. 

The five birds recorded in figure 35 showed no distinct character different 
from those shown in figures 32 to 34. 



o^ 



30 



Earl W. Benjamin 






<5ecor7cf c/ears Th/n/ (/ears /ov/tih (/ears f/rffo (/ears S/*/fy years 
Index proa'ucf product* _ . ^oroduc/^. , ^.^prrx/ae^ • •• • ^prcK/c/c/^^^ 

11 



76 
75 
74 
73 

72 

71 

70 

69 

68 
67 



Month 1st 




11th 



Fig. 33. monthly variation in shape of eggs produced during a period of six 

YEARS • 
The figures in parenthesis designate the number of birds available for the respective calculations 



Study of Selections for Size, Shape, and Color of Hens' Eggs 261 



Index 
76 

75 

74 

73 

72 

71 

70 

69 

68 

67 

66 

65 

Month 1st 



B/rc/s w/f/7 //Ye /77ea/7 of 

60-65 TO -75 . 

65-70 75-BO iiinini 



















" 








-«■ ,8; 


(12) 












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soi 




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f-4* 


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\ 








\ 




3/ 








\ 


fg] 


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\ 




















\ 




















1 


(i; 



2d 



3d 



4th 



5th 6th 



7th 8th 



9th 



10th 11th 



Fig. 34. monthly variation in shape of eggs produced during a period of six 

YEARS 

The figures in parenthesis designate the number of birds available for the respective calculations 

The curve representing the birds having a life mean of 60-65 does not lie entirely within that range 

because the whole six-years data on which the life mean is based is not available in monthly means for 

this chart 



262 



Earl W. Benjamin 



■^a Sv'rsf years Second c/ecrrs Zh/rJ ' t/ears /hurf/7 t/e&rs /v/?/7 c/ears 

r< vW/y/^ /?roe/tscfm— — . — ^proc/c^c/^mm . — . _ proc/c*cf+*mm prot/ucf** • • 

75 



74 

73 

72 

71 

70 

69 

68 









— • ^» 


•"^. 










/ 


^_* «^^ 






• 








• ^ 


• [ ^^ ^ 




s^^**« 


h^» 

^^*^*^_ 


/ 




/ 


^ „ 








^^■^s 


L / 






••••^J^TT" 




V \ 






/ 


^ /••_ 




"is 








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o 


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• 


• 


• 


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e 


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• 


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• 


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e 
• 


• 

• 




6" 








1 


■ 


» 


»*••••», 


r ' 
















/ 
















/ 




















- 













Dec. Jan. Feb. March April 



May 



June 



July Aug. 



Fig. 35. mean monthly shape records for five normal individuals for a period 

OF five years 

These results do not agree with deductions to be gained from Curtis 
(1914 a) or from Thompson (1908). It would appear from these results that 
the tension of the oviduct wall may gradually relax during the first five or 
six months of the bird's production each year, and then increase again as the 
season closes, causing at first a rounding of the egg and later a lengthening. 

Color character 

The study of the monthly production as to the variations of color is 
summarized in figures 36 to 39. There is a definitely increased amount 
of pigment in the eggs produced by the hens after their pullet year as 
compared with their first year's production (fig. 36). There is a distinct 
tendency for the eggs to become whiter as the production continues for 
the first five or six months, and then to become more tinted again toward 
the end of the season's production. It would seem that the amount of 
pigment is decreased during the period of most abundant egg production. 

As shown in figure 37, there is no distinct and gradual increase in the 
pigmentation of the eggs from the second to the sixth year's production, 
but during each year when enough birds are available for the data to be 
considered of value, there is a tendency for the same monthly fluctuations 
as are exhibited in figure 36. The grouping of the birds according to their 
life means in figure 38 shows the same monthly fluctuations as were 
previously observed. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 263 



A7ea/7 for -first 
Color years prodt/cf 

5. o 

5.6 

5.4 

5.2 

5.0 

•1.8 

4.6 

4.4 

4.2 

4.0 

3.8 

3.6 

3.4 

3.2 

3.0 

2.8 

2.6 

2.4 4 

2.2 



A7&a/7 for 3eco/7a' fo 
s/xf/7 years prodacr. 



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10240 




















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J432) 


flaO 


02Si— ^* 


*T99) 




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X 










t7<*) ^. 


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N. 


u& 7 L 


(126) 




(10!)^, ** 




(5W > 


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11th 



Month 1st 2d 3d 4th 5th 6th 7th 8th 9th 10th 

Fig. 36. monthly variation in color of eggs produced during a period of six 

YEARS 

The figures in parenthesis designate the number of birds available for the respective calculations 



264 



Earl W. Benjamin 



<Secanc/ t/ecrrs 7?7/re/ t/ears fhurfft 
prvc/ucf proe/ucf— — — —proc/iso 

?oior r~ r I I " i i 



proc/csc/-— . — . —proc/ucf 



. . —proc/uc/ mm, proc/c/c/ +*** 




Month 1st 2d 3d 4th 5th 6th 7th 8th 9th 10th 11th 

Fig. 37. monthly variation in color of eggs produced during a period of six 

YEARS 

The figures in parenthesis designate the number of birds available for the respective calculations 



Study of Selections for Size, Shape, and Color of Hens' Eggs 265 



Birds tv/fn //Ye mean of 
/-a — <*-5 

3 — f ._ <8-7 — o— 7- &•••• 




Month 1st 2d 3d 4th 

Fig. 38. monthly vacation in color of eggs produced during a per.od of six 



YEARS 






The figures 



in parenthesis designate the number of birds available for the respective calculations 



266 



Earl W. Benjamin 



The results of this study agree in general with the findings of other 
workers, already discussed. 

The record of five individuals in figure 39 agrees in general with the 
records in figures 36 to 38. 



> > 9 j ■ j 

//as/ c/e-ars Secorx/ yeo/3- Z/7/'rc/ </ecrrs /bu///? years /v///? </ears 
proouc? ' —~/oroc/ucf '«_ — « /?roc/c/cf—. . _. ^.jPrcx/uc:? ( proc/ucf* • • • « 



Color 


















5 


o\ 


















o\ 










i 

s 


i 






\\ 













9 X 






o 








< 


• „ 


• 
• 


• jf 




A. (\- 


Vy 






• 
• 


**•• 


a 
• 


• / 








, »»«« 


'« 


• 
• 


••J 


• 

9 










V 




m 

• 






/* 




0.0 


^- 


■^ « 


*••, 


\" ^ 


V 




/ • 




3 


V 






r** 


N 




• 












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N 




• 




2^5— 






/"^ 




^^N 




V 






* "-^V» 




jS 






*c ^ 


A 




9 ft 




*" 








V^xJ 


CSV 


1 
















r>^ 


1.5 












•n 


/ "^ 



Dec. 



Jan. 



Feb. March April May June July Aug. 



Fig. 39. mean monthly color records for five normal individuals for a period 

of five years 



Variations in types of successive individual eggs 

An opportunity is furnished by figures 18, 21, and 24 (pages 243, 246, 
and 249) to observe how the types of successive eggs may be affected b} T 
the general type of the bird and the rate of laying. 

In figure 18 it may be noted that in nearly every instance when two or 
more eggs are laid on successive days, the size gradually diminishes until 
the bird rests for one or more days, when the size of the next egg is again 
larger. This agrees with many more charts constructed for this same 
character, and is in entire accordance with Curtis (1914 a). 

A study of figure 21, which agrees in general with other charts constructed 
for the shape character but not reproduced here, reveals the fact that in 
a large proportion of the instances when two or more eggs are laid in 
succession, the egg laid later is rounder than the one laid earlier. About 
60 per cent of the cases showed an increase in the index, 25 per cent showed 
no change, and 15 per cent showed a decrease. This condition may 



Study of Selections for Size, Shape, and Color of Hens' Eggs 267 



result from the less tension exerted by the oviduct wall on the second 
egg when it closely follows an earlier one. After the bird has rested for 
a day ©r two, the oviduct wall regains its tension and the next egg is longer. 
The egg color, for the birds that were studied in this regard, seemed 
to be gradually intensified in eggs kid on successive days (fig. 24). About 
50 per cent of the cases showed an intensification of color, 25 per cent 
showed no change, and 25 per cent showed a decrease of color. 

Variations in types of eggs produced in different calendar months 

Since it is known that the commercial eggs received in the markets 
vary somewhat from month to month as to their average size and color, 
and possibly as to their shape, it was thought well to ascertain what 
information could be obtained on this point from the data at hand. These 
variations for size, shape, and color, respectively, are illustrated in figures 
40, 41, and 42. 

The results shown in figure 40 do not agree with those of Hadley (1919), 
but tend instead to agree in general form with figures 28, 29, and 30. 

Grama 



u-s - 




















60 






























' 










58 








































56 








































54 




























': 












S2 





















Feb. 



March 



April 



May- 



June 



July 



Aug. 



Sept. 



Oct. 



Njv. 



Fig. 40. mean monthly variation in size of eggs produced in certain calendar 
i months for a period of six years. record of ten individuals beginning to 
lay in february 

No increase of egg size during the period of heavier production can be 
observed here, as found by Hadley (1919) with White Plymouth Rocks. 

The results shown in figures 41 and 42 agree closely with the results 
previously obtained for mixed flocks, and need no further comment 
here. 



268 



Earl W. Benjamin 




Jan 



Feb. S March 1 



Oct. 



April ] Z;L May j June ] July Aug, Sept. 

Fig 41, mean monthly variation in shape of eggs produced in certain cm f^ap 
™7a™a A r Y PERI ° D ° F SIX YEARS " REC0RD of ten ^SS^S^SS^i 




Feb. * March 

M0 4 N 2 THS M FOR N A "SS 0^™,^°* ° F EGGS PR ° DUCED IN CER ™* »»»»> 
LAY IN FEBRUARY ' REC0RD » OT ™ INDIVIDUALS BEGINNING TO 



Study of Selections for Size, Shape, and Color of Hens' Eggs 269 



Relation between vigor of the chick and size of the egg from which it was hatched 
In 1911-12 a separate record of the vigor of the chicks, as well as of their 
weight, was made for the first forty weeks of their lives. The vigor was 
recorded in four classes: Very Poor (V.P.), Poor (P), Good (G), Very 
Good (V.G.). Correlation tables such as table 59 were constructed 

TABLE 59. Vigor of Chicks at the Age of Four Weeks, Subject; Weight (in Grams) 
of Eggs from Which the Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .381 ± .064 



V. P. 

P. 

G. 
V.G. 



44-46 46-48 48-50 50-52 


52-54 


54-53 


56-58 


58-60 60-62 62-64 64-66 


1 
1 3 

5 1 
5 


1 
6 
4 


1 
5 

8 


1 
4 
8 


1 1 
3 1 2 

2 8 4 4 









11 



14 



13 



10 



1 
9 

27 
43 

80 



for each four weeks of the chicks' lives. A summary of the results of 
the correlation tables (space for which cannot be taken here) is given in 
table 60. In this table the respective weight correlations also are shown. 

TABLE 60. Summary of Coefficients of Correlation Found in Studying the 
Relation of the Weight and Vigor of the Chicks, Subject, and the Weight of 
the Eggs from Which the Respective Chicks Were Hatched, Relative 



Age of chick 


Coefficient of correlation 


Number 
of indi- 


Chick vigor 


Chick weight 


viduals 


1 day 


* 


.844±.021 
.461 ±.060 
.311 ±.067 
.362 ±.068 
.380±.068 
.263±073 
.308±.072 
.296±077 
.509±.064 
.392±074 
.397±079 


82 


4 weeks 


. 381 ±. 034 
.331 ±.066 
.334±069 
.338±.070 
.159±077 
.176±.077 
.174±081 
.296±.080 
.075±.087 
.110±.093 


80 


8 weeks 


82 


12 weeks . 


75 


16 weeks 


72 


20 weeks 


73 


24 weeks. ... 


73 


28 weeks 


65 


32 weeks 


61 


36 weeks 


60 


40 weeks 


51 







* The vigor was not recorded at the one-day-old period, because it was impossible to designate the dif- 
ferent classes at this early age. 

In recording the data for these vigor studies, a special effort was made 
to be sure that the record for vigor was made independently of the record 



270 



Earl W. Benjamin 



for weight. Of course these two factors are likely to be very closely 
associated. The weight correlations are much more distinct than those 
for vigor during most of the year. The vigor correlations decreased 
after the early weeks, until some very severe winter weather just previous 
to the thirty-sixth week's recording. After the thirty-sixth week, how- 
ever, abnormally early spring weather prevailed, the vigor of all birds 
improved wonderfully, and the correlation entirely disappeared. 

From the observations just noted, it seems that the test of the vigor 
of a chick, that is to say, when the size of the parent egg is of real 
benefit, comes during the season of greatest hardship to the birds. The 
weights are not affected by the seasonal conditions quite so definitely as is 
the vigor. 

Relation between male and female weights for chicks of the same age 

During the first forty weeks of the 1911 hatch, and the first seventy-six 
weeks of the 1912 hatch, the male and female weights were averaged 



TABLE 61. Constants Representing X in the Formula: 

Weight : : X : 1 



Female Weight : Male 



1911 offspring 


1912 offspring 


Age 


Constant 


Age 


Constant 




.89 
.91 
.81 
.78 
.75 
.75 
-.88 
.89 
.92 
.90 


1 day 


.97 


4 weeks 


4 weeks 


.72 


8 weeks 


8 weeks 

12 weeks 

16 weeks 

20 weeks 

24 weeks 

23 weeks 


.84 


12 weeks 


.86 


16 weeks 


.88 


20 weeks 


.87 


2-1 weeks 


* 


28 weeks 


.95 


32 weeks 


32 weeks 

33 weeks 

40 weeks 

44 weeks 

48 weeks 

52 weeks 


.91 


36 weeks 


.95 


40 weeks 


.94 




.83 
.89 


* 


56 weeks 


.84 




60 weeks 

64 weeks 


.81 
.82 




68 weeks 


.85 




72 weeks 


.82 




76 weeks 


.S3 









* No male weights were obtained at this age in 1912. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 271 

separately, and for each four-weeks period a figure was obtained to rep- 
resent x in the following ratio: 

Female weight : male weight :: x : 1 

A list of all such constants obtained is shown in table 61. In studying 
correlations for the weeks shown in table 61 for the 1911 offspring, and 
for the one-day-old period of the 1912 offspring, the male weights were 
multiplied by their respective constants and used with the female 
weights. After the above periods, and for all other offspring, no male 
weights were used. These constants correspond rather closely to the con- 
stant 0.93 representing the same ratio for human stature in mature per- 
sons, found by Galton. 11 

Relation between size of the chick and size of the egg from which it was hatched 

A preliminary study was made of the 1911 and 1912 offspring, before 
the records for the later years were available, to determine the relation 
between the size of the chick and the size of the egg from which it was 



Er / 


9//crffepf?hg—-< 


.«=» __ 




56 1 






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J_ 




































43 ' 








. , 




A It 












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' 




_ 










































Jl 
















































"I 




































































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-*"v^ 


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— 


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- *' 1 ' '■ ' t ' 1 ' 1 ' t « ?* ' 


>— — 



8 16 24 32 40 48 56 64 72 80 88 96 104 112 120 128 136 144 152 160 168 176 184 192 200 208 216 224 
Week 4 12 2Q 28 36 44 52 60 68 76 84 92 100 108 116 124 132 140 148 156 164 172 180 188 196 204 212 220 

Fig. 43. graphic record of ~ for 191 i offspring, 1912 offspring, and all birds 
available during the period of the experiment 

Sizes of birds at four-weeks periods during their life, subject; sizes of eggs from which the respective 
chicks were hatched, relative 



11 Galton, Francis. Natural inheritance, p. 78. 1889. 



272 



Earl W. Benjamin 



hatched (Benjamin, 1912 and 1914). The coefficients of correlation for 
these preliminary studies are summarized in table 62 and in figure 43. 

TABLE 62. Summary of Preliminary Studies to Determine the Relation between 
Size of the Chick and Size of the Egg from Which It Was Hatched 





1911 offspring 


1912 offspring 


Age of chicks 


Coefficient 

of 
correlation 


r 
Er 


Number 
of indi- 
viduals 


Coefficient 

of 
correlation 


r 
Er 


Number 
of indi- 
viduals 


1 day 


.844±.021 
.461 ±.060 
.311±.067 
.362±.068 
.380±.068 
.263±.073 
.308±.072 
.296±.077 
.509±.064 
.392±.074 
.397±.079 
.458±.081 
.355±.090 
.353±.089 
.355±.089 
.308±.092 
.340±.090 
.370±.089 
.363±.089 
.224±.098 
.315±.093 
.276±.095 
.056±.103 
.549±.073 
.441±.083 
.492±.079 
.441±.084 
.356±.093 
.270±.099 
.222±.102 
.164±.104 
.337±.095 
.368±.093 


40.19 
7.68 
4.64 
5.32 
5.59 
3.60 
4.28 
3.84 
7.95 
5.30. 
5.03 
5.65 
3.94 
3.97 
3.99 
3.33 
3.78 
4.16 
4.08 
2.29 
3.39 
2.91 
0.64 
7.52 
5.31 
6.23 
5.25 
3.83 
2.73 
2.18 
1.58 
3.55 
3.96 


82 
80 
82 
75 
72 
73 
73 
65 
61 
60 
51 
44 
43 
44 
44 
44 
44 
43 
43 
43 
43 
43 
43 
42 
42 
42 
42 
40 
40 


.745±.017 
.024±.050 
.074±.058 
.099±.059 
.088±.063 
.046±.039 
.301 ±.082 
.363±.076 
.401 ±.055 
.350±.058 
.420±.057 
.506±.052 
.378±.062 
.328±.066 
.310±.067 
.367±.067 
.405±.054 
.246±.071 
.331 ±.025 
.409±.O75 

- 


43.82 
0.48 
1.28 
1.68 
1.40 
0.67 
3.67 
4.78 
7.29 
6.03 
7.37 
9.73 
6.10 
4.97 
4.63 
5.48 
6.33 
3.46 

13.24 
5.45 


308 


4 weeks 


179 


8 weeks 


134 


12 weeks 


125 


16 weeks 


110 


20 weeks 


96 


24 weeks 


56 


2$ weeks 


59 


32 weeks 


108 


36 weeks 


104 


40 weeks 


96 


44 weeks 


92 


48 weeks 


88 


52 weeks 


83 


56 weeks 


82 


60 weeks 


80 


64 weeks 


77 


68 weeks 


79 


72 weeks 


78 


76 weeks 


56 


80 weeks 




84 weeks 




88 weeks 




92 weeks 




96 weeks 




100 weeks 




104 weeks 




108 weeks 




112 weeks 




116 weeks 


40 
40 




120 weeks 




124 weeks 


40 
40 

1 


i 




128 weeks 









In both years the value r seems to have been higher during cold weather, 
which occurred, for the 1911 offspring, from the thirtieth to the forty- 
fourth week and from the ninety-second to the one-hundredth week, 
and for the 1912 offspring from the thirtieth to the forty-fourth week. 
This seems to be due to the fact that the larger, stronger birds were 



Study of Selections for Size, Shape, and Color of Hens' Eggs 273 

able to withstand the severe winter weather relatively better than the 

smaller birds from the smaller eggs. 

r 
A similar tendency may be noted for the -pr. to increase during the 

first winter, in the curve representing all birds in figure 43, but no 
definite increase in this factor can be observed for any of the later 
winters. No definite tendency can be seen toward an increase or a 

r 

decrease in the factor t=c as the birds b3come older after the fourth week. 

r 

The factor ^r at the one-day age is very large, as might be expected. 

From the fourth week to the twentieth week of the 1912 offspring, it 
will be noticed that the coefficient of correlation is very low. The only 
explanation of this is that it may be due to an error in taking the weights. 
The balance used was rather heavy, and the hundredths of pounds had 
to be estimated. It is possible that the flapping and jumping of the larger, 
more vigorous chicks caused their weight to be underestimated, thus tend- 
ing to reverse the correlation. In spite of these few discrepancies, it will be 
noted that the correlation is always positive and in most cases significant. 

The studies that were made on all available birds during the entire 
experiment are shown in tables 63 to 119, and are summarized in figure 
43 (page 271) and in table 120. 

TABLE 63. Size (Weight in Grams) of Birds at Age of 1 Day, Subject; Size of Eggs 
from Which Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .73 db .013 





44 


46 


48 


50 


52 


54 


55 


58 


60 


62 


61 


63 


68 


70 


23-25 






1 
























25-27 




7 


7 
























27-29 




8 


17 


6 


8 


1 


1 




1 












29-31 




5 


15 


17 


20 


16 


6 


2 


1 












31-33 


1 




3 


11 


23 


39 


21 


6 


2 












33-35 




2 


1 


11 


12 


19 


26 


22 


5 


4 










35-37 






1 


2 


5 


4 


14 


24 


23 


10 


1 








37-39 




1 






3 


13 


6 


10 


8 


10 


7 


2 






39-41 












4 


3 


7 


9 


8 


7 


4 






41^3 












2 


3 


3 


6 


3 


4 


4 


1 




43-45 
















1 


1 






2 


1 




45-47 




























1 


47-49 
















1 






1 








49-51 


























1 


1 


51 or more 








1 























1 

14 

42 

82 

109 

102 

84 

60 

42 

26 

5 

1 

2 

2 

1 



1 23 45 48 74 98 80 76 56 35 20 12 3 2 573 



274 



Earl W. Benjamin 



TABLE 64. Size of Birds at Age op 4 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .20 =fc .037 



2a 30 

30- 40 

40- 50 

50- 60 

60- 70 

70- 80 

80- 90 

90-100 

100-110 

110-120 

120-130 

130-140 

140-150 

150-160 

160-170 

170-180 

180-190 

\1 90-200 

200-210 

210-220 

220-230 

230-240 

240-250 



44 


45 


48 


50 


52 


54 


56 


58 


60 


62 


64 


66 


68 


70 




1 


1 




2 


1 


1 




1 
1 
















1 




3 


4 


4 


1 


2 


1 














1 


1 


1 




2 


1 
















1 


1 


2 


2 


5 


1 


1 


6 














1 


2 


1 




2 




2 


1 


2 














4 


2 


1 


2 


1 


2 


3 














1 


5 


7 


7 


10 


6 


5 


4 


1 


1 


1 








2 


1 


2 


4 


8 


5 


5 


3 


5 


2 






1 


1 


1 


1 


2 


4 


10 


9 


7 


4 


2 


3 


2 


1 








1 




2 


3 


5 


5 


4 


4 


1 






1 








1 


5 


4 


5 


6 


1 




1 


2 


1 


2 










2 


1 


1 


3 


1 


2 


1 


1 












1 


1 


1 

1 


1 


2 


1 


1 


1 


1 












1 


1 
1 


1 


1 
1 


2 

1 
1 


1 


1 














1 








1 

















7 19 20 35 53 44 44 33 19 10 



5 
3 

16 

6 

19 

11 

15 

48 

38 

47 

26 

28 

12 

6 

5 

4 

1 

3 

2 



1 

1 

2 

299 



Study of Selections for Size, Shape, and Color of Hens' Eggs 275 



TABLE 65. Size of Birds at Age of 8 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .14 db .038 



44 46 48 50 52 54 55 58 60 62 64 66 68 70 



80-100 
100-120 
120-140 
140-160 
160-180 
180-200 
200-220 
220-240 
240-260 
260-280 
280-300 
300-320 
320-340 
340-360 
360-380 
380-400 
400-420 
420-440 
440-460 





1 




1 

2 


1 


3 




* 










1 


4 


1 


2 


3 


1 


1 


1 






1 


4 


3 


2 


1 


2 


2 


2 






1 


5 


1 


6 


4 


1 
i 


3 


2 










4 


4 


7 


4 


4 


2 


2 


1 


1 






3 


3 


9 


2 


7 


4 






1 






3 


6 


8 


7 


4 


1 


1 










2 


4 


2 


5 


4 


3 


5 


2 


1 


1 


1 


2 


5 


1 


6 


7 


2 


1 


3 


2 


2 




1 




6 


4 


3 


1 


1 


1 


1 




2 




1 


2 


2 


5 


3 


1 


1 










5 


3 


3 ' 


4 


3 


3 












1 


1 


1 


1 


1 












1 


1 


1 



















7 19 22 37 53 44 44 31 19 11 7 



1 

2 

3 

8 

16 

19 

24 

32 

34 

33 

31 

32 

21 

16 

22 

5 

1 

1 

1 

302 



276 



Earl W. Benjamin 



TABLE 63. Size of Birds at Age of 12 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .20 ± .040 



44 46 48 50 52 54 56 58 60 62 64 66 68 70 



300-320 








1 


1 


1 




2 




1 


6 


320-340 
















1 






1 


340-360 


1 




2 


2 


3 




1 


2 


1 




12 


360-380 


1 


1 


1 




3 






2 






8 


380-400 






1 


1 


2 




2 








6 


400-420 




1 


1 


1 


3 


2 


1 


1 


1 


1 1 


13 


420-440 


2 


1 




1 


2 


2 


2 


1 


1 




12 


440-460 


2 


3 


1 


6 


1 


2 






1 ] 




17 


460-480 


1 


1 


1 


1 


2 




2 


3 


1 




12 


480-500 




3 


2 


2 


3 


5 


3 


1 






20 


500-520 




1 












1 






2 


520-540 




1 


2 


3 


2 


4 


2 


3 


1 


1 


19 


540-560 










8 


6 


6 


1 


1 ] 


[ 1 1 


25 


560-580 






1 


1 


3 




3 


5 


2 2 1 


IS 


580-600 




2 




5 


2 


3 






1 


2 


15 


600-620 




1 


2 


1 


5 


2 


3 


1 






16 


620-640 


1 


1 


1 


1 


2 


3 


4 


1 






14 


640-660 








1 




3 


2 




1 




7 


660-680 






1 


2 






1 




1 ] 


I 2 


8 


680-700 






1 


1 


2 


2 


1 


2 




J 1 


13 


700-720 










1 


2 


1 


2 






6 


720-740 








1 




1 


1 




3 ] 




7 


740-760 


















1 




1 


760-780 














1 




1 




2 


780-800 








1 










1 




2 



1 7 16 17 32 45 38 36 29 18 11 7 



262 



Study of Selections for Size, Shape, and Color of Hens' Eggs 277 



TABLE 67. Size of Birds at Age op 16 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .19 ± .040 



360- 400 

400- 440 

440- 480 

480- 520 

520- 560 

560- 600 

600- 640 

640- 680 

680- 720 

720- 760 

760- 800 

800- 840 

840- 880 

880- 920 

920- 960 

980-1000 

1000-1040 

1040-1080 

1080-1120 

1120-1160 

1160-1200 

1200-1240 

1240-1280 



44 


46 


48 


50 


52 


54 


56 


58 


60 


62 


64 


66 


68 


70 
























1 










1 


1 
2 

2 




1 
2 


3 
1 


1 

1 


3 
1 


1 












1 




2 


3 


o 
O 




3 


1 














1 






1 


2 




1 


2 


1 






1 






1 


1 


' 2 


2 


1 


4 


4 




1 










1 


2 


1 




1 


2 


1 


3 


1 
















2 


2 


2 


2 


2 


2 






2 






1 




1 


2 


1 


2 


4 


2 




3 


2 














2 


1 


3 


4 


2 


2 




1 


1 






1 






1 


4 




5 


3 


3 


3 


2 




1 










2 


2 


3 


5 


4 


2 


1 








1 






1 


2 




4 


4 


3 


6 


9 




1 
















1 


3 


7 


3 




3 


2 


1 










1 


1 


2 


2 


1 


,2 


















1 




2 


1 


1 


1 


1 


1 


















1 


1 


1 
3 

2 


1 

2 




3 
1 
1 


4 
1 


1 
1 
1 














2 




1 


1 




1 








. 










1 


- 



















1 7 16 20 30 42 41 38 25 18 11 6 2 



1 

7 

7 

6 

13 

9 

16 

12 

15 

17 

17 

22 

20 

30 

20 

9 

8 

12 

8 

4 

4 

1 

1 



259 



278 



Earl W. Benjamin 



TABLE 68. Size of Birds at Age op 20 Weeks, Subject; Size op Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .18 ± .040 



400- 500 

500- 600 

600- 700 

700- 800 

800- 900 

900-1000 

1000-1100 

1100-1200 

1200-1300 

1300-1400 

1400-1500 



44 46 


48 


50 


52 


54 


55 


58 


60 


62 


64 


63 


68 


70 




1 


1 
3 


3 




1 
2 


1 
1 


3 
1 












1 




3 




3 


1 


4 


1 


2 




1 


1 




7 


3 


5 


4 


5 


5 


5 


6 


3 








1 


1 


2 


5 


9 


13 


10 


10 


3 




5 


1 




1 




4 


5 


3 


12 


8 


5 


9 


1 


4 


2 


1 






1 


2 


5 


6 


2 


8 


8 


4 


2 


3 


2 






2 




2 
1 


1 


6 
1 


4 
1 


4 


1 


1 


2 










13 24 27 40 36 39 35 11 12 9 4 2 



, 2 

5 

10 

17 

44 

60 

54 

43 

23 

2 

1 

261 



TABLE 69. Size op Birds at Age of 24 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .15 ± .066 



600- 700 

700- 800 

800- 900 

900-1000 

1000-1100 

1100-1200 

1200-1300 

1300-1400 

1400-1500 

1500-1600 

1600-1700 

1700-1800 

1800-1900 



46 


48 


50 


52 


54 


56 


58 


60 


62 


64 


66 


68 70 




1 




1 
1 






1 


1 


















1 


o 
o 


1 


3 


1 


1 






3 


2 


2 


1 


2 


3 


1 


2 






1 


1 


1 


1 


3 


4 


7 


1 


4 




1 


2 




1 




1 


3 


4 


4 


6 


4 


7 




1 








2 


1 


1 


4 


2 


5 


6 


2 


1 


2 


1 




1 




2 
1 


2 


1 
1 
3 


2 
2 


2 
1 


1 


3 


3 





8 9 15 20 20 20 22 



8 6 



2 
2 
1 

10 
18 
25 
30 
27 
15 

r 

o 
3 
1 
1 

140 



Study of Selections for Size, Shape, and Color of Hens' Eggs 279 



TABLE 70. 






Size of Birds at Age of 28 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 



44 



Coefficient of correlation = .12 ± .039 
46 48 50 52 54 56 58 60 62 64 66 68 70 



600-700 






1 










1 












2 


700- 800 




1 










1 














2 


800- 900 






1 








1 


2 












4 


900-1000 




1 


3 


6 


2 


1 




2 


1 




1 






17 


1000-1100 


3 




2 




6 


3 


3 


5 


2 






1 




25 


1100-1200 


1 2 


2 


4 


9 


10 


6 


10 


6 




1 






2 


53 


1200-1300 


3 




5 


4 


6 


6 


8 


6 


1 


4 


1 


2 


1 


47 


1300-1400 




6 


6 


5 


11 


7 


3 


6 


1 


3 


1 


1 


1 


51 


1400-1500 




1 


1 


4 


7 


6 


6 


5 


2 


3 


2 


1 




38 


1500-1600 






1 


1 


2 


5 


5 


2 


1 




3 






20 


1GOO-1700 




2 


1 


1 


1 


2 


1 


3 


1 




1 






13 


1700-1800 




1 




2 


2 


1 


2 














8 


1800-1900 








1 








1 


2 










4 


1900-2000 












1 


1 














2 


2000-2109 































2100-2200 































2200-2300 
















1 












1 



14 25 33 47 38 41 40 11 11 9 



287 



TABLE 71. Size of Birds at Age of 32 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coafficient of correlation = .31 ± .036 



700- 
800- 
900- 
1000- 
1100- 
1200- 
1300- 
1400- 
1500- 
1600- 
1700- 
1800- 
1900- 
2000- 
2100- 
2200- 



- 800 
900 
1000 
1100 
1200 
1300 
1400 
1500 
1600 
1700 
1800 
1900 
2000 
2100 
2200 
2300 



44 


46 


48 


50 


52 


54 


56 


58 


60 


62 


64 


66 


68 


70 






1 


1 
1 










1 












1 


2 


1 


2 
3 


1 


1 

1 


1 


1 


2 


2 












1 




1 


7 


4 


1 


5 


2 






1 


1 






1 


1 


2 


6 


6 


7 


9 


3 




2 






1 




3 


3 


7 


5 


10 


4 


2 


10 




1 




2 








3 


5 


5 


11 


10 


6 


8 


1 


2 


2 




2 






4 


4 


4 


9 


5 


6 


3 


2 


1 


1 








1 






3 


4 


8 


2 


4 


2 


2 


1 


1 


1 






1 




1 


2 


2 


6 
2 
1 

1 


2 
2 

1 


1 
1 

2 


1 
1 
1 


2 
1 

1 


1 





14 26 32 48 38 41 38 11 11 9 



1 

7 

11 

23 

38 

47 

55 

39 

29 

15 

9 

4 

1 

3 

1 

286 



280 



Earl W. Benjamin 



TABLE 72. Size of Birds at Age of 36 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .33 ± .037 .] J ,~\ 
44 46 48 50 52 54 53 58 60 62 64 65 68 70 



700- 800 


1 














1 










2 


800- 900 





























900-1000 






2 


1 


















3 


1000-1100 




1 


1 


1 


1 




1 












5 


1100-1200 


2 




1 


3 


3 


1 




3 


1 








14 


1200-1300 


3 




6 


3 


3 


4 


7 


2 


1 






1 


30 


1300-1400 




3 


4 


3 


7 


7 


8 


4 


1 


3 


1 


1 


42 


1400-1500 


2 


5 


5 


8 


9 


6 


6 


6 


1 








48 


1500-1600 


1 


1 


5 


5 


7 


7 


4 


6 


2 


3 


2 


1 2 


46 


1600-1700 




1 


1 


1 


10 


6 


7 


3 


1 




2 


1 1 


34 


1700-1800 




1 




3 


2 


4 


1 


3 




2 






16 


1800-1900 










2 


3 


4 


4 




2 


3 




18 


1900-2000 




1 










2 




1 




1 


1 


6 


2000-2100 


















1 


1 






2 


2100-2200 














1 


1 










2 


2200-2300 






— 












1 








1 



1 8 13 25 28 44 



41 33 10 11 9 



269 



TABLE 73. Size of Birds at Age of 40 Weeks, Subject; Size of Eggs from" Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .28 ± .038 
46 48 50 52 54 56 58 60 62 64 66 68 70 



900- 


-1000 
















1 












1 


1000- 


-1100 






1 


1 




















2 


1100- 


-1200 






2 






















2 


1200- 


-1300 


1 


1 


2 


6 


3 




2 


3 












18 


1300- 


-1400 


3 


1 


6 


6 


9 


6 


4 


7 


1 






1 




44 


1400- 


-1500 


3 


3 


4 


6 


10 


7 


10 


7 


3 


4 


3 


1 




61 


1500- 


-1600 




6 


8 


3 


12 


7 


10 


1 


1 


2 




1 


1 


52 


1600- 


-1700 






3 


5 


6 


6 


6 


5 


2 


1 






2 


36 


1700- 


-1800 




2 




5 


4 


5 


3 


7 


1 


1 


2 






30 


1800- 


-1900 










3 


2 


2 


1 


1 


1 


2 




1 


13 


1900- 


-2000 














2 


3 


1 










6 


2000- 


-2100 






















1 






1 


2100- 


-2200 































2200- 


-2300 














1 




1 










2 


2300- 


-2400 
















1 












1 



7 13 26 32 47 33 40 36 11 9 



239 



Study of Selections for Sizjs, Shape, and Color of Hens' Eggs 281 



TABLE 74. Size of Birds at Age of 44 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .34 ± .035 



1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 



46 


48 


50 


52 


54 


53 


58 


60 


62 


64 


66 


68 


70 










1 






1 
















1 


2 


1 






1 












3 


1 


4 


4 


3 


2 


2 


4 


1 










1 


3 


5 


11 


9 


3 


4 


6 








1 




3 


3 


8 


4 


15 


8 


8 


4 


3 


1 


1 




1 




3 


4 


4 


9 


8 


9 


5 


i 

X 


3 


1 


1 


2 




2 


2 


6 


5 


3 


8 


7 


1 


3 


2 


1 








1 


1 


2 
1 


8 
2 


1 

2 
1 

1 


6 

1 

1 


3 
1 
1 


2 


1 
2 


1 


1 



7 12 25 32 46 34 36 36 11 9 7 



2 

5 

24 

43 

59 

50 

40 

25 

10 

3 



2 

263 



TABLE 75. Size of Birds at Age of 48 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .27 ± .039 
46 48 50 52 54 53 58 60 62 64 66 68 70 



900-1000 








1 




















1 


1000-1100 






1 


1 






1 


1 












4 


1100-1200 


1 


1 


5 


2 




2 


1 


3 








1 




16 


1200-1300 


4 




6 


2 


11 


6 


4 


5 


2 










40 


1300-1400 




2 


5 


12 


7 


5 


9 


3 


4 


2 


1 




2 


52 


1400-1500 


2 


6 


5 


6 


12 


6 


7 


7 




2 


2 


1 




56 


1500-1600 




3 


2 


2 


10 


7 


5 


9 


1 


1 




2 


1 


43 


1600-1700 








4 


1 


5 


6 




3 


1 


3 




1 


24 


1700-1800 








1 


3 


2 


1 


6 




2 








15 


1800-1900 










1 










1 


1 






3 


1900-2000 














2 














2 


2000-2100 
















1 


1 










2 



7 12 24 31 45 33 38 35 11 



258 



282 



Earl W. Benjamin 



TABLE 76. Size of Birds at Age of 52 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .25 =b .039 
46 48 50 52 54 53 58 60 62 64 63 68 70 



900- 


-1000 








1 




















1 


1000- 


-1100 






3 










2 












5 


1100- 


-1200 


1 


1 


4 


3 


1 


1 


3 


4 


1 


1 








20 


1200- 


-1300 


4 




2 


8 


5 


5 


7 


2 


3 






1 


1 


38 


1300- 


-1400 


1 


4 


8 


3 


22 


8 


4 


6 


1 


1 


1 


1 


1 


61 


1400- 


-1500 




5 


4 


10 


11 


9 


7 


8 


2 


2 


1 


1 


1 


61 


1500- 


-1600 




3 


1 


2 


6 


6 


7 


4 


1 


2 


1 






33 


1600- 


-1700 








3 


1 


3 


4 


3 


2 


1 


1 






18 


1700- 


-1800 








2 


2 


2 


3 


4 




2 


2 




1 


18 


1800- 


-1900 































1900- 


-2000 































2000- 


-2100 














1 


1 












2 


2100- 


-2200 


















1 










1 



6 13 22 32 48 34 33 34 11 9 6 3 4 258 



TABLE 77. Size of Birds at Age of 58 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .28 =b .039 
46 48 50 52 54 56 58 60 62 64 66 68 70 



700- 800 
800- 900 
900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 























•' 


1 








5 


1 






1 


2 












2 


1 


1 


o 
o 


6 


5 


2 


3 


1 










4 


2 


6 


11 


7 


5 


4 


6 


1 


1 






1 




6 


3 


4 


15 


7 


10 


5 


2 


2 


1 




2 




2 


5 


10 


10 


o 
o 


4 


9 


1 




1 


1 






1 


1 


1 


8 


7 


9 


4 


1 


2 


1 


1 






1 




2 




7 


2 


1 


1 


2 


1 










1 




2 




3 
1 


2 
1 

1 


3 

1 


2 


2 




1 



6 13 22 32 48 34 86 34 11 9 6 3 4 



1 





9 

24 

48 

57 

43 

33 

17 

13 

4 





3 

258 



Study of Selections for Size, Shape, and Color of Hens' Eggs 283 



TABLE 78. Size of Birds at Age op 60 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatcekd, Relative 

Coefficient of correlation = .37± .037 
43 48 50 52 54 58 53 60 62 61 65 68 70 



700- 800 










1 
















1 


800- 900 






1 




















1 


900-1000 








2 








1 










3 


1000-1100 






6 


1 




1 














8 


1100-1200 


o 
O 


2 


3 


5 


a 


1 


2 


4 


2 








25 


1200-1300 


2 


1 


3 


7 


8 


2 


5 


3 








1 


32 


1300-1400 


1 


2 


4 


5 


13 


9 


4 


5 


1 


2 


2 




48 


1400-1500 




5 


3 


r 

o 


8 


8 


9 


8 


3 






1 


48 


1500-1600 




1 


2 


5 


9 


2 


6 


5 




3 




2 


35 


1300-1700 




2 




1 


5 


7 


6 


3 






1 


1 


26 


1700-1800 










2 


3 


3 


1 


2 


1 


2 


1 


15 


1800-1900 








1 




1 




1 


2 


3 


1 




9 


1900-2000 


















1 








1 


2000-2100 














1 












1 


2100-2200 





























2200-2300 
















1 










1 



6 13 22 32 47 34 36 32 11 9 6 



254 



TABLE 79. Size of Birds at Age of 64 Weeks, Subject; Size of Eggs from Which 

P Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .40 ± .035 

43 48 50 52 54 53 58 60 62 64 66 68 70 



800- 


- 900 








1 


1 
















2 


900- 


-1000 






1 








1 












2 


1000- 


-1100 






3 


o 


















5 


1100- 


-1200 


1 


1 


3 


2 


5 


1 


1 


3 


1 








18 


1200- 


-1300 


4 


3 


3 


8 


9 


7 


3 


4 


1 


1 




1 


44 


1300- 


-1400 


1 


2 


6 


6 


13 


8 


10 


7 


2 


4 




1 


60 


1400- 


-1500 


• 


5 


3 


5 


9 


6 


6 


4 


2 


1 


2 1 




44 


1500- 


-1600 




2 


1 


3 


4 


6 


7 


5 






1 1 




30 


1600- 


-1700 








3 


4 


3 


5 


4 


1 




2 


2 


24 


1700- 


-1800 










2 


2 


2 


2 






1 




9 


1800-1900 








1 








2 


3 


3 






9 


1900- 


-2000 





























2000- 


-2100 












1 




1 


1 








o 


2100- 


-2200 














1 












1 



6 13 20 31 47 34 . 36 32 11 9 6 



251 



284 



Earl W. Benjamin 



TABLE 80. Size of Birds at Age of 68 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .30 ± .039 



800- 
900- 
1000- 
1100- 
1200- 
1300- 
1400- 
1500- 
1600- 
1700- 
1800- 
1900- 
2000- 
2100- 
2200- 
2300- 



900 
1000 
1100 
1200 
1300 
1400 
1500 
1600 
1700 
1800 
1900 
2000 
2100 
2200 
2300 
2400 



46 


48 


50 . 


52 


54 


58 


58 


60 


62 


64 


66 


68 


70 






1 




2 






















4 


1 


1 




1 


2 












2 


2 


3 


2 


2 


2 


4 


1 






1 






3 


1 


5 


5 


12 


3 


4 


4 


1 










1 


1 


3 


8 


9 


6 


3 


3 


o 


2 






1 




2 


4 


7 


4 


7 


6 


3 


1 


o 
o 


2 


1 


1 




4 


1 


5 


9 


4 


5 


6 


3 


1 




1 






2 




2 


6 


8 


8 


4 




1 


1 




1 










1 


2 


4 


4 


1 


1 


2 








1 












1 


















1 


1 


1 


1 


1 

1 


1 

1 








1 



1 

2 

9 

19 

38 

40 

41 

39 

33 

15 

2 

7 





1 

1 



6 13 21 31 47 33 33 30 11 8 6 2 4 248 



TABLE 81. Size of Birds at Age of 72 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .29 ± .040 



: ivi 



46 48 50 52^54 55 58 60 62 64 66 68 70 



800 


- 900 






1 




















1 


900- 


-1000 




1 






1 
















2 


1000- 


-1100 








2 


1 
















3 


1100- 


-1200 


3 




6 




4 


1 




2 










13 


1200 


-1300 


1 


1 


3 


1 


6 


2 


4 


1 


1 


1 






21 


1300- 


-1400 


2 


2 


6 


5 


7 


7 


7 


4 


2 


1 


1 1 


2 


47 


1400- 


-1500 




o 
o 


4 


8 


9 


7 


6 


4 




2 


1 




44 


1500- 


-1600 




3 




6 


8 


3 


7 


10 


4 


3 


1 




45 


1600- 


-1700 




2 




4 


6 


6 


4 


2 


1 


2 


1 


2 


30 


1700- 


-1800 




1 




4 


2 


4 


3 


6 






1 




21 


1800- 


-1900 










1 


2 


2 




2 




1 




8 


1900- 


-2000 












1 










1 




2 


2000- 


2100 










1 
















1 


2100- 


-2200 














1 












1 


2200- 


-2300 





























2300- 


■2400 





























2400- 


-2500 
















1 


1 








2 



6 13 20 30 46 33 34 30 11 9 6 2 4 244 



Study of Selections for Size, Shape, and Color of Hens' Eggs 285 



TABLE 82. Size of Birds at Age of 76 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .26 ± .043 
4G 48 50 52 54 56 58 60 62 64 66 68 70 



900-1000 




1 












1 








2 


1000- 


-1100 






2 


1 


1 














4 


1100- 


-1200 






1 




1 














3 


1200- 


-1300 


1 




4 




5 


2 


2 


1 




1 1 




17 


1300- 


-1400 


3 


2 


5 


3 


10 


6 


5 


3 ] 


L 1 




1 


40 


1400- 


-1500 


2 


4 


3 


8 


4 


4 


10 


7 


1 


2 




45 


1500- 


-1600 




2 




4 


4 


7 


6 


4 ] 


L 2 


1 




31 


1600- 


-1700 




1 


2 


3 


6 


3 


3 


4 I 


5 2 




1 


28 


1700- 


-1800 




1 




5 


3 


5 


2 


2 1 


2 


1 


1 


23 


1800- 


-1900 








2 


3 


1 


2 


4 


1 






13 


1900- 


-2000 










1 


3 


2 










7 


2000- 


-2100 












1 












2 


2100- 


-2200 










2 










2 




4 


2200- 


-2300 
















1 








1 


2300- 


-2400 














1 


1 








2 


2400- 


-2500 



























2500- 


-2600 



























2600- 


-2700 
















1 








1 



6 11 17 23 40 32 33 28 10 9 6 



223 



TABLE 83. Size of Birds at Age of 80 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .24 ± .048 



900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 
2500-2600 



46 


48 


50 


52 


54 


56 


58 


60 


62 


64 


66 


68"] 70 








1 




















1 


2 
1 




2 








1 








1 




4 


2 


2 




2 


1 


1 






1 


2 




2 


3 


9 


2 


7 


6 


1 


1 




1 1 


1 


2 


1 


4 


4 


5 


5 


5 










1 


1 




2 


2 


5 


4 


2 


1 


1 










2 


2 


5 


1 


4 


2 


3 


1 








1 




5 


4 


5 




2 




2 




1 








1 


2 


1 


2 


4 




3 




1 




1 






2 


3 

2 


2 

1 


1 
1 


1 
2 









6 12 20 32 24 27 24 10 8 5 



1 

3 

4 

15 

35 

28 

19 

20 

21 

14 

6 

5 

4 

1 

1 



1 

178 



286 



Earl W. Benjamin 



TABLE 84. Size of Birds at Age of 84 Weeks, Subject; Size of Eggs feom Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .33 ± .054 
46 48 50 52 54 56 58 60 62 64 66 08 70 



900- 


-1000 








1 


















1 


1000- 


-1100 





























1100- 


-1200 










2 
















2 


1200- 


-1300 






3 




1 
















4 


1300- 


-1400 


1 






1 


3 


1 


2 


1 


1 






1 


11 


1400- 


-1500 




2 


3 


3 


3 


4 


3 


1 










19 


1500- 


-1600 


2 


1 


1 


2 


4 


5 


1 


4 


1 




1 




22 


1600- 


-1700 




1 




2 


1 


3 


1 


3 


1 






1 


13 


1700- 


-1800 








2 


3 


2 


2 


3 


1 


3 






16 


1800- 


-1900 




1 




2 


3 


1 


2 


2 




1 




1 


13 


1900- 


-2000 










3 


5 


1 


2 


1 


2 






14 


2000- 


-2100 










1 


1 


1 




1 




1 




5 


2100- 


2200 














1 








1 




2 


2200- 


-2300 


















1 








1 


2300- 


-2400 





























2400- 


-2500 














1 


1 










2 



7 13 24 22 15 17 



125 



TABLE 85. Size of Birds at Age of 88 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .30 ± .057 
46 48 50 52 54 56 58 60 62 64 66 68 70 



900- 


-1000 






1 
















1 


1000- 


-1100 

























1100- 


-1200 




1 


















1 


1200- 


-1300 








1 


1 












2 


1300- 


-1400 




2 


1 


1 






1 








5 


1400- 


-1500 


1 






2 




2 


3 


1 




1 1 


11 


1500- 


-1600 


1 3 


2 


4 


3 


6 


1 


2 


1 




1 


24 


1600- 


-1700 




3 


1 


3 


3 


3 


2 


1 


1 




17 


1700- 


-1800 


1 




3 


2 


2 


2 


3 


1 


2 




16 


1800- 


-1900 








4 


5 


2 










11 


1900- 


-2000 






1 


1 


1 


3 


2 






1 


9 


2000- 


-2100 


1 




1 


3 


1 




1 


2 


1 


1 


11 


2100- 


-2200 




















1 


1 


2200- 


-2300 














1 


2 


1 




4 


2300- 


-2400 

























2400- 


-2500 












1 










1 


2500- 


-2600 

























2600- 


-2700 














1 








1 



5 8 12 20 19 14 16 



1 1 



115 



Study of Selections for Size, Shape, and Color of Hens' Eggs 287 



TABLE 86. Size of Birds at Age of 92 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .30 ± .055 
46 48 50 52 54 56 58 60 62 64 66 68 70 



1200 


-1300 






1 


1 


















2 


1300- 


-1400 






2 




1 






2 


1 








6 


1400- 


-1500 


1 


1 


1 


1 


5 


2 


2 


1 








1 


15 


1500- 


-1600 


1 


2 




3 


7 


4 


3 


5 






1 




26 


1600- 


-1700 




1 


1 


2 




2 


3 


1 


2 


2 






14 


1700- 


-1800 


1 




2 


3 


4 


4 


2 


3 


1 


2 


1 




23 


1800- 


-1900 








1 


3 


2 


2 


1 








1 


10 


1900- 


-2000 








1 


2 


2 


1 


1 


1 






1 


9 


2000- 


-2100 










1 


3 


1 


2 




1 






8 


2100- 


-2200 












1 






1 


1 


1 




4 


2200- 


-2300 




1 














1 




1 




3 


2300- 


-2400 





























2400- 


-2500 














1 




1 








2 


2500- 


-2600 
















1 










1 



5 7 12 23 20 15 17 



6 4 



123 



TABLE 87. Size of Birds at Age of 96 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .40 ± .051 



46 48 50 52 54 56 58 60 62 64 66 68 70 



1100- 


-1200 






1 




















1 


1200- 


-1300 


1 
























1 


1300- 


-1400 




1 


1 


3 


3 


2 




2 


2 








14 


1400- 


-1500 


1 


1 


2 


4 


6 


4 


2 


3 










23 


1500- 


-1600 


1 


2 


1 


2 


5 


3 


4 


4 






1 




23 


1600- 


-1700 






1 


3 


3 


3 


2 


4 


2 


3 


1 


1 


23 


1700- 


-1800 










3 


5 




1 




1 




1 


11 


1800- 


-1900 










3 




4 












7 


1900- 


-2000 












2 




2 


1 




1 


1 


7 


2000- 


-2100 












1 


1 




2 




1 




5 


2100- 


-2200 




1 
















2 






3 


2200- 


-2300 














1 












1 


2300-2400 














1 


1 


1 








3 






























— 



5 6 12 23 20 15 17 8 6 4 



122 



288 



Earl W. Benjamin 



TABLE 88. Size of Bieds at Age of 100 Weeks, Subject; Size of Eggs feom Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .35 ± .055 



46 48 50 52 54 56 58 60 62 64 66 68 70 



1100- 


-1200 






1 


1 


















2 


1200- 


-1300 


1 




2 


1 


1 


1 




2 










8 


1300 


-1400 


1 






2 


3 


1 


1 


3 


1 








12 


1400- 


-1500 


1 


3 


1 


3 


7 


5 


2 


1 


2 






1 


26 


1500- 


-1600 




1 


1 


2 


3 


2 


5 


3 




1 


2 


1 


21 


1600- 


-1700 






1 




3 


1 


2 


3 


2 








12 


1700- 


-1800 








2 


3 


3 


2 






3 






13 


1800- 


-1900 










2 


2 


1 


2 








1 


8 


1900- 


-2000 












1 


1 


1 


1 




1 




5 


2000- 


-2100 












1 






1 


2 






4 


2100- 


-2200 




1 


















1 




2 


2200- 


-2300 


















1 








1 


2300- 


-2400 





























2400- 


-2500 














1 












1 



6 11 22 17 15 15 8 6 4 



115 



TABLE 89. Size of Birds at Age of 101 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .32 =fc .057 



46 48 50 52 54 56 58 60 62 64 66 68 70 



1000- 


-1100 
























1 


1100- 


-1200 


1 




1 1 








1 










4 


1200- 


-1300 








3 


2 


1 


3 


1 








11 


1300- 


-1400 




1 


1 1 


5 


1 


2 




1 








12 


1400- 


-1500 


1 


2 


1 4 


.3 


5 


2 


1 


1 




1 


1 


22 


1500- 


-1600 


1 




2 


3 


1 


2 


5 


1 


1 






16 


1600- 


-1700 




1 


1 2 


2 


1 


2 


3 




2 


1 


1 


16 


1700- 


-1800 






1 


4 


4 


3 


1 




2 


1 




16 


1800- 


-1900 










1 


1 




1 








3 


1900- 


-2000 








1 






1 


1 






1 


4 


2000- 


-2100 




1 






2 








1 






4 


2100- 


-2200 
















2 








2 


2200-2300 












1 








1 




2 



3 5 6 11 21 17 14 15 8 6 4 2 



113 



Study of Selections for Size, Shape, and Color of Hens' Eggs 289 



TABLE 90. Size of Birds at Age of 103 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .34 ± .056 



46 48 50 52 54 56 58 60 62 64 66 68 70 



1000- 


-1100 






1 










1 










2 


1100- 


-1200 


1 




2 










1 










4 


1200- 


-1300 








1 


2 


2 




1 


1 








7 


1300- 


-1400 


1 






2 


7 


3 


1 


3 


1 








18 


1400- 


-1500 




2 


2 


2 


4 


3 


2 


1 








1 


17 


1500- 


-1600 


1 


2 


1 


4 


1 


1 


3 


3 


2 


1 


1 




20 


1600- 


-1700 








2 


4 


2 


2 


2 




1 


1 




14 


1700- 


-1800 










2 


1 


4 


1 


1 


2 




1 1 


13 


1800- 


-1900 










1 


3 


1 


2 


1 




1 




9 


1900- 


-2000 




1 














1 


2 






4 


2000- 


-2100 












1 














1 


2100- 


-2200 












1 






1 




1 




3 


2200- 


-2300 





























2300-2400 














1 












1 






























— 



6 11 21 17 14 15 8 6 



1 113 



TABLE 91. Size of Birds at Age of 112 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .25 ± .060 



900-1000 
1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 



46 


48 


50 


52 


54 


56 


58 


60 


62 


64 


66 


68 70 






1 
























1 












1 








1 




1 




1 






3 


1 










1 




3 


5 


5 


1 


1 


1 






1 


1 


2 


2 


4 


6 


1 


2 


3 


1 


2 






1 


1 


1 


1 


2 


3 


3 


4 




1 


2 


1 








1 


3 


1 


3 


1 




1 


1 


1 








2 


4 


3 
2 


1 
3 


1 

1 


2 


2 








1 








1 


1 


1 


1 
1 




1 





6 11 21 16 14 15 8 6 4 



1 
1 
1 

7 

18 

24 

20 

12 

11 

10 

4 



2 



1 

112 



299 



Earl W. Benjamin 



TABLE 92. Size of Birds at Age of 116 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .28 ± .059 
46 48 50 52 54 56 58 60 62 64 66 68 70 



1000-1100 
1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 







1 












1 








2 




1 


1 


1 
1 


1 


1 




2 










4 
4 


1 






2 


3 


3 


2 


2 


1 




1 


1 


16 




1 


3 


1 


3 


1 




3 


2 








14 


2 


1 


1 


3 


9 


3 


3 


2 




2 






23 




1 




2 


2 


1 


4 


2 




2 


1 




15 










1 


3 


1 


1 




1 




1 


8 








1 


2 


2 


1 




1 




1 


1 


9 




1 


- 






1 

1 


2 
1 


3 


2 
1 


1 


1 




10 


2 

1 
1 



6 11 21 13 14 15 8 6 4 



1 112 



TABLE 93. Size of Birds at Age of 120 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .29 ± .059 . 
46 48 50 52 54 53 5S 60 62 64 63 68 70 



1000- 


-1100 


















1 








1 


1100-1200 






1 


2 


















3 


1200- 


-1300 




1 


3 




1 


1 










1 




7 


1300- 


-1400 


1 






1 


2 






3 




1 






8 


1400- 


-1500 


1 


1 






3 


2 


2 


1 


2 


1 




1 


14 


1500- 


-1600 


1 


2 


2 


4 


9 


5 


2 


4 




1 






30 


1600- 


-1700 








3 


4 


1 


2 


5 


1 


2 


1 


1 


20 


1700- 


-1800 










1 


1 


2 








1 


1 


6 


1800- 


-1900 




1 








2 


2 


1 










6 


1900- 


-2000 










1 


1 


3 




1 








6 


2000- 


-2100 












1 






1 




1 




3 


2100- 


-2200 




















1 






1 


2200- 


-2300 












1 






1 








2 


2300- 


-2400 


















1 








1 



6 10 21 15 13 14 8 



108 



Study of Selections for Size, Shape, and Color of Hens' Eggs 291 



TABLE 94. Size of Birds at Age of 124 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .41 ± .054 



1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1300-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 



46 


48 


50 


52 


54 


53 


58 


60 


62 


64 


66 


68 


70 












2 








1 










3 






2 


1 


1 


















4 


2 


3 


2 


1 


1 


1 


1 




1 










12 




1 


1 


1 


5 


1 




5 


1 


1 








16 


1 






2 


6 


3 


1 


2 


1 


2 




1 




19 


• 




1 


5 


2 


6 


4 


4 




2 




1 




25 










3 


3 


3 


1 






2 




1 


.13 




1 






1 


1 


2 
1 

1 


2 
1 


1 
1 

2 


1 


1 
1 






8 
4 
1 
2 
2 



6 10 21 15 13 15 8 



109 



TABLE 95. Size of Birds at Age of 128 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .33 ± .069 
45 47 49 51 53 55 57 59 61 63 65 67 



1200- 


-1300 


1 




1 


2 


2 








1 






7 


1300- 


-1400 






2 




3 






2 


1 




1 


9 


1400- 


-1500 




3 


1 


2 


2 


1 


4 


2 




1 




16 


1500- 


-1600 


1 






1 


1 


3 


2 


1 


1 




1 


11 


1600- 


-1700 






1 




3 


3 




1 


2 




1 


11 


1700- 


-1800 












1 


3 






2 




6 


1800- 


-1900 
















1 








1 


1900- 


-2000 




1 






1 




2 


1 


1 




1 


7 


2000- 


-2100 












1 




1 




1 


1 


4 


2100- 


-2200 










1 




1 










2 


2200- 


-2300 


















1 






1 



5 13 9 12 9 



1 j 75 



292 



Earl W. Benjamin 



TABLE 96. Size of Birds at Age of 132 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .42 ± .074 
45 47 49 51 53 55 57 59 61 63 65 



1100- 


-1200 




1 


















1 


1200- 


-1300 






1 


2 












1 


4 


1300- 


-1400 


2 


1 




2 






1 


1 






7 


1400- 


-1500 


1 


1 






1 








1 




4 


1500- 


-1600 


1 






2 


3 


2 


3 








11 


1600- 


-1700 








2 


1 


1 




3 






7 


1700- 


-1800 






1 


2 


1 


4 






1 




9 


1800- 


-1900 


1 












1 




1 


1 


4 


1900- 


-2000 








1 




1 










2 


2000- 


-2100 










1 




2 




1 




4 


2100- 


-2200 












1 








1 


2 


2200- 


2300 

























2300- 


-2400 




















1 


1 



2 11 



56 



TABLE 97. Size of Birds at Age of 136 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .44 db .077 
45 47 49 51 53 55 57 59 61 63 65 



1000- 


-1100 






1 


















1 


1100- 


-1200 



























1200- 


-1300 



























1300- 


-1400 


1 


1 


1 






1 




1 






1 


6 


1400- 


-1500 


1 


1 


1 


















3 


1500- 


-1600 








1 


1 




1 


1 




1 




5 


1600- 


-1700 






1 




4 


1 


1 










7 


1700- 


-1800 




1 




1 


1 


1 




2 


2 




1 


9 


1800- 


-1900 




1 






1 


1 


1 


1 




1 




6 


1900- 


-2000 












1 


2 


1 




2 


1 


7 


2000- 


-2100 














1 










1 


2100- 


-2200 










1 


1 




1 








3 


2200- 


-2300 






















1 


1 


2300- 


-2400 














1 




1 






2 



2 4 



8 6 



51 



Study of Selections for Size, Shape, and Color of Hens' Eggs 293 



TABLE 98. Size of Birds at Age of 140 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .41 ± .071 



45 47 49 51 53 55 57 59 61 63 65 



1100-1200 




1 


















1 


1200-1300 

























1300-1400 






1 










1 






2 


1400-1500 




2 




2 








1 




1 


6 


1500-1600 


2 2 








1 




2 








7 


1600-1700 










1 


2 


2 




1 




6 


1700-1800 


1 




1 


6 


1 


3 




1 






13 


1800-1900 




1 


1 


3 




1 


1 






1 


8 


1900-2000 


1 








1 


3 




1 






6 


2000-2100 










2 




1 




2 




5 


2100-2200 














1 






1 


2 


2200-2300 












1 


1 




1 


1 


4 


2300-2400 

























2400-2500 












1 










1 


2500-2600 
















1 






1 



2 4 



3 11 6 11 8 



62 



TABLE 99. Size of Birds at Age of 144 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .44 ± .074 



45 47 49 51 53 55 57 59 61 63 65 



1100-1200 












1 










1 


1200-1300 




1 


1 










1 






3 


1300-1400 








1 














1 


1400-1500 


' 






1 






1 








2 


1500-1600 


2 2 


1 




2 




2 


2 






1 


12 


1600-1700 


1 


2 




1 


1 


2 










7 


1700-1800 






2 


1 


1 


1 


2 








7 


1800-1900 








3 


1 


1 








1 


6 


1900-2000 








1 


1 


1 


1 








4 


2000-2100 














2 


1 




1 


4 


2100-2200 












1 






1 


1 


3 


2200-2300 












1 






1 




2 


2300-2400 












1 










1 


2400-2500 

























2500-2600 ' 
















1 






1 



3 10 4 11 



2 4 



54 



294 



Earl W. Benjamin 



TABLE 100. Size of Birds at Age of 148 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .49 ± .070 
45 47 49 51 53 55 57 59 61 63 65 



1200-1300 




2 
















2 


1300-1400 






1 






1 


1 






3 


1400-1500 


2 1 




2 




2 


2 








9 


1500-1600 




1 


3 4 


1 


3 


1 






1 


14 


1600-1700 


2 


1 


1 






1 








5 


1700-1800 










2 


1 






1 


4 


1800-1900 






2 


3 


1 










6 


1900-2000 










2 


1 






1 


4 


2000-2100 










1 


1 


1 




1 


4 


2100-2200 
















1 




1 


2200-2300 




- 












1 




1 


2300-2400 























2400-2500 























2500-2600 























2600-2700 























2700-2800 














1 






1 



3 4 3 10 4 11 



2 4 



54 



TABLE 101. Size of Birds at Age of 152 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .52 ± .068 
45 47 49 51 53 55 57 59 61 63 65 



1200-1300 






1 


















1 


1300- 


-1400 


2 






1 








1 








4 


1400- 


-1500 




1 






4 


1 


1 


1 


1 






9 


1500- 


-1600 




2 


1 


1 


2 




2 


2 






1 


11 


1600- 


-1700 






1 


1 


3 


1 


4 


1 






2 


13 


17*00- 


-1800 














2 










2 


1800- 


-1900 












2 


1 


1 


1 






5 


1900- 


-2000 
















2 




1 




3 


2000- 


-2100 




















1 




1 


2100- 


-2200 














1 








1 


2 


2200- 


-2300 


















1 






1 




2 


3 


3 


3 


9 


4 


11 


8 


3 


2 


4 


52 



Study of Selections for Size, Shape, and Color of Hens' Eggs 295 



TABLE 102. Size of Birds at Age of 156 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .50 ± .078 





-1200 




-r • 


Af\ 






55 


57 


59 


61 


63 


65 




1100- 






1 


















1 


1200- 


-1300 








l 


1 














2 


1300- 


-1400 


2 




1 




1 




1 




1 






6 


1400- 


-1500 




1 






3 


1 


1 


1 








7 


1500- 


-1600 




2 




I 




1 


2 


2 






2 


10 


1600- 


-1700 






1 


1 






3 








1 


6 


1700-1800 










2 




1 


1 








4 


1800- 


-1900 












1 




1 


1 






3 


1900- 


-2000 




















1 




1 


2000- 


-2100 




















1 




1 


2100-2200 


















1 






1 




























— 



42 



TABLE 103. Size of Birds at Age of 160 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .48 ± .072 



1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 



45 47 


49 


51 


53 


55 


57 


59 


61 


63 


65 


1 


1 


1 


1 




1 










1 1 


1 




3 






1 


1 






1 




1 


2 




2 








3 


1 


1 


1 


1 

1 
1 


1 
1 
1 

1 


3 
3 

1 
1 


4 

1 
2 


1 
1 


1 
1 


1 



2 3 



9 4 11 8 



5 

8 
9 
12 
5 
3 
4 
3 

3 

52 



296 



Earl W. Benjamin 



TABLE 104. Size of Birds at Age of 164 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .43 ± .078 
45 47 49 51 53 55 57 59 61 63 65 



1200- 


-1300 






1 


















1 


1300- 


-1400 


1 








1 




1 




1 






4 


1400- 


-1500 


1 


1 






1 






2 






1 


6 


1500- 


-1600 




2 




1 


2 


1 


1 


1 








8 


1600- 


-1700 






2 


1 


1 


1 


3 


2 






1 


11 


1700- 


-1800 










2 




2 








1 


5 


1800- 


-1900 










1 


2 


1 










4 


1900- 


-2000 














2 


2 


1 


1 




6 


2000- 


-2100 
















1 








1 


2100- 


-2200 


















1 




1 


2 


2200- 


-2300 




















1 




1 


2300- 


-2400 



























2400- 


-2500 



























2500- 


-2600 














1 










1 



2 3 3 2 8 4 11 



3 2 4 



50 



TABLE 105. Size of Birds at Age of 168 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .50 =fc .072 
45 47 49 51 53 55 57 59 61 63 65 



1100- 


-1200 






i 
















1 


1200- 


-1300 

























1300- 


-1400 


1 




















1 


1400- 


-1500 


1 


1 


1 


2 




1 


2 


1 




1 


10 


1500- 


-1600 




2 




2 3 




1 


1 






1 


10 


1600- 


1700 








2 




2 


2 








6 


1700- 


-1800 






1 




3 


3 








1 


8 


1800- 


-1900 








1 




3 


2 








6 


1900- 


-2000 










1 






1 


1 




3 


2000- 


-2100 












1 










1 


2100- 


-2200 




















1 


1 


2200- 


-2300 
















1 


1 




2 



8 4 11 7 



49 



Study of Selections for Size, Shape, and Color of Hens' Eggs 297 



TABLE 103. Size of Birds at Age op 172 Weeks, Subject; Size op Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .52 =b .070 



1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 



45 47 49 51 53 55 57 59 61 63 65 




TABLE 107 Size of Birds at Age of 176 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative - 
Coefficient of correlation = .44 ± .082 



1000- 
1100- 
1200- 
1300- 
1400 
1500 
1600- 
1700 
1800 
1900 
2000 



1100 
1200 
1300 
-1400 
-1500 
-1600 
-1700 
-1800 
-1900 
-2000 
-2100 



45 47 49 51 53 55 57 59 61 63 65 



2 


1 

6 
7 
8 
3 
8 
6 
3 

44 



298 



Earl W. Benjamin 



TABLE 108. Size of Birds at Age of 180 Weeks, Subject; Size of Eggs fbom Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .37 ± .108 



45 47 49 51 53 55 57 59 61 83 65 



1000-1100 






1 














1 


1100- 


-1200 























1200- 


-1300 


















1 


1 


1300- 


1400 










1 










1 


1400- 


1500 


2 


2 








1 


1 






6 


1500- 


-1600 








1 


1 










2 


1600 


-1700 






1 






1 


1 




1 


4 


1700- 


-1800 






1 


1 


1 




1 


1 




5 


1800- 


-1900 










1 


2 






1 


4 


1900- 


-2000 












1 1 


2 


1 




5 



2 4 15 



29 



TABLE 109. Size of Birds at Age of 184 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .52 ± .085 



45 47 49 51 53 55 57 59 61 63 65 



1100- 


-1200 






1 
















1 


1200- 


-1300 

























1300- 


-1400 


1 






1 














2 


1400- 


-1500 


1 


1 












1 






3 


1500- 


-1600 




1 










2 








3 


1600- 


-1700 






1 




1 




1 


3 


1 


1 


8 


1700- 


-1800 








1 


3 


1 










5 


1800- 


-1903 










1 




3 




1 




5 


1900- 


-2000 












1 


1 


1 






3 


2000- 


-2100 




















1 


1 


2100- 


-2200 














1 


1 






2 


2203- 


-2300 
















1 






1 



34 



Study of Selections for Size, Shape, and Color of Hens' Eggs 299 



TABLE 110. Size of Birds at Age of 188 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .60 ± .099 
45 47 49 51 53 55 57 59 



1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 



1 

I 


1 


1 


1 


1 

1 


1 
1 


1 
1 

1 • 2 

1 

1 

1 
1 1 
1 



2 

1 
2 

2 
4 
1 
2 

2 
2 
1 

19 



TABLE 111. Size of Birds at Age of 192 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .59 ± .079 



1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 




2 2 2 2 5 2 



300 



Earl W. Benjamin 



TABLE 112. Size of Birds at Age of 196 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .48 ± .093 



45 47 49 51 53 55 57 59 61 63 



1200-1300 




1 












1 


1300-1400 



















1400-1500 










1 


1 




2 


1500-1600 


2 1 






2 








5 


1600-1700 


1 






1 




1 




3 


1700-1800 






1 


1 


2 


1 




5 


1800-1900 




1 




1 




1 




3 


1900-2000 






1 




2 2 


1 




6 


2000-2100 










1 


2 




3 


2100-2200 










1 




1 


2 


2200-2300 



















2300-2400 



















2400-2500 



















2500-2600 



















2600-2700 










1 






1 



2 2 2 2 5 2 



7 



31 



TABLE 113. Size of Birds at Age of 200 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .56 ± .084 i 



45 47 49 51 53 55 57 59 61 63 



1000- 


-1100 






1 












1 


1100- 


-1200 





















1200- 


-1300 





















1300- 


-1400 


1 
















1 


1400- 


-1500 




1 








1 






2 


1500- 


-1600 




1 




1 


2 








4 


1600- 


-1700 


1 




1 




1 


1 


3 




7 


1700- 


-1800 














1 




1 


1800- 


-1900 










1 


2 


2 




5 


1900- 


-2000 








1 




2 1 


1 




5 


2000 


-2100 










1 








1 


2100- 


-2200 












1 






1 


2200- 


-2300 












1 






1 


2300-2400 
















1 


1 






















— 



2222527701 



30 



Study of Selections for Size, Shape, and Color of Hens' Eggs 301 



TABLE 114. Size of Birds at Age of 204 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .66 ± .068 

45 47 49 51 53 55 57 59 61 63 



1100-1200 






1 












1 


1200-1300 





















1300-1400 


1 


1 














2 


1400-1500 


1 
















1 


1500-1600 




1 


1 


2 






1 




5 


1600-1700 








2 2 


1 


2 


2 




9 


1700-1800 












2 


1 




3 


1800-1900 












2 






2 


1900-2000 










1 




3 




4 


2000-2100 








1 




1 






2 


2100-2200 
















1 


1 


2200-2300 












1 






1 



1 



31 



TABLE 115. Size of Birds at Age of 208 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .49 ± .092 



1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 
2300-2400 
2400-2500 




2222528701 



302 Earl W. Benjamin 



TABLE 116. Size of Birds at Age of 212 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .68 ± .085 



1100- 
1200- 
1300- 
1400- 
1500- 
1600- 
1700- 
1800- 
1900- 
2000- 
2100- 
2200- 
2300- 
2400- 



1200 
1300 
1400 
1500 
1600 
1700 
1800 
1900 
2000 
2100 
2200 
2300 
2400 
2500 



45 47 49 


51 


53 


55 


57 


59 


61 


63 


1 
















1 
















1 2 




1 


1 


1 








1 


2 


3 
1 


1 


1 

2 
2 
1 

1 


3 

1 

2 
1 




1 



1 



1 



1 

3 
3 
10 
2 
3 
4 
3 



1 

31 






TABLE 117. Size of Birds at Age of 216 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 



1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 
2100-2200 
2200-2300 



45 47 


49 


51 


53 


55 


57 59 


61 63 




1 












1 1 






1 








1 




1 


1 








1 


1 


1 


1 
1 


1 

1 


1 2 
1 2 

1 1 

2 1 
1 

1 


1 



2 8 7 



1 
3 
4 
3 
5 
4 
3 
3 
2 
1 
1 

30 



Study of Selections for Size, Shape, and Color of Hens' Eggs 303 



TABLE 118. Size op Birds at Age of 220 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 



Coefficient of correlation = .69 ± .034 
45 47 49 51 53 55 57 59 61 



63 



1200- 


-1300 




1 














1 


1300- 


-1400 


2 1 
















3 


1400- 


-1500 


1 




1 


1 


1 








4 


1500- 


-1600 








1 




1 


1 




3 


1600- 


-1700 








2 




2 


1 




5 


1700- 


-1800 






1 






1 


3 




5 


1800- 


-1900 




1 








1 


1 




3 


1900- 


-2000 










1 


3 


1 




5 


2000- 


-2100 





















2100- 


-2200 
















1 


1 



2 4 



30 



TABLE 119. Size of Birds at Age of 224 Weeks, Subject; Size of Eggs from Which 
Respective Chicks Were Hatched, Relative 

Coefficient of correlation = .40 ± . 103 



1100-1200 
1200-1300 
1300-1400 
1400-1500 
1500-1600 
1600-1700 
1700-1800 
1800-1900 
1900-2000 
2000-2100 



45 47 


49 


51 


53 


55 


57 


59 


61 63 




1 










1 




1 




1 












2 






1 




1 


1 




1 




1 


1 
1 
1 


1 


1 
2 
1 


2 
1 

1 






1 






1 


1 
1 
1 


1 


1 



1 



1 

1 

2 
5 
7 
4 
3 
4 
2 
1 

30 



304 



Earl W. Benjamin 



TABLE 120. Summary of Tables 63 to 119. Size of Birds at Four-Weeks Periods 
during Their Life, Subject; Size of Eggs from Which Respective Chicks Were 
Hatched, Relative 



Age of chicks 


Coefficient 

of 
correlation 


r 

eT 


Number 
of indi- 
viduals 


1 day . . 


.73±.013 
.20±.037 
.14±.038 
.20±040 
. 19± .040 
.18±.040 
.15±.066 
.12±.039 
31±036 
33±037 
.28±.038 
34±035 
.27±039 
.25=b.039 
.28±.039 
.37±.037 
.40±.036 
.30±.039 
.29±.040 
.23±.043 
.24±.048 
.33±.054 
.30±057 
.30±055 
.40±051 
.35db.055 
.32±.057 
.34±.056 
.25±.060 
.28±.059 
.29±.059 
.41±.054 
.33±.069 
.42=b.074 
.44±.077 
.41±.071 
.44±.074 
.49±.070 
.52d=.068 
.50±.078 
.48±072 
.43±078 
50±072 
.52±.070 
.44±.082 


56.15 
5.41 
3.68 
5.00 
4.75 
4.50 
2.27 
3.08 
8.61 
8.92 
7.37 
9.71 
6.92 
6. 41 
7.18 
10.00 
11.11 
7.69 
7.25 
6.05 
5.00 
6.11 
5.26 
5.45 
7.84 
6.36 
5.61 
6.07 
4.17 
4.75 
4.92 
7.59 
4.78 
5.68 
5.71 
5.77 
5.95 
7.00 
7.65 
6.41 
6.67 
5.51 
6.94 
7.43 
5.37 


573 


4 weeks . . 


299 


8 weeks 


302 


12 weeks 


262 


16 weeks 


259 


20 weeks 


261 


24 weeks 


140 




287 


32 weeks 


286 


36 weeks 


269 


40 weeks 


269 


44 weeks. 


263 


48 weeks 


258 


52 weeks 


258 




258 


60 weeks 


254 


64 weeks 


251 


68 weeks 


248 


72 weeks 


244 


76 weeks . , 


223 


80 weeks 


178 


84 weeks 


125 


88 weeks 


115 


92 weeks 


123 


96 weeks 


122 


100 weeks 


115 


104 weeks 


113 


108 weeks 


113 


112 weeks .' 


112 


116 weeks 


112 


120 weeks. 


108 




109 




75 


132 weeks 


56 


136 weeks. . 


51 


140 weeks 


62 


144 weeks 


54 


148 weeks 


54 


152 weeks 


52 


156 weeks 


42 


160 weeks 


52 


164 weeks 


50 


168 weeks .• 


49 


172 weeks 


50 




44 



Study of Selections for Size, Shape, and Color of Hens' Eggs 305 
I 

TABLE 120 (concluded) 



Age of chicks 


Coefficient 

of 
correlation 


r 
Er 


Number 
of indi- 
viduals 


180 weeks 


.37±.108 
.52±.085 
.60±.099 
.59±.079 
.48±093 
.56±084 
.66±.068 
.49=b.092 
.68±.065 
.66±070 
.69=b.064 
.40±.103 


3.43 
6.12 
6.06 
7.47 
5.16 
6.67 
9.71 
5.33 

10.46 
9.43 

10.78 
3.88 


29 


184 weeks 


34 


188 weeks 


19 


192 weeks 


31 


196 weeks 


31 


200 weeks 


30 


204 weeks 


31 


208 weeks 


31 


212 weeks 


31 


216 weeks 


30 


220 weeks 


30 


224 weeks • 


30 



DISCUSSION OF RESULTS 

The results of these studies are neither in entire accord nor in entire 
discord with any of the important studies of the same factors made by 
other workers. Up to the present time no extensive work has been 
reported on Single Comb White Leghorn material. So far as is known 
by the writer, no other study of these particular factors has been made 
with similar lines of inheritance over as long a period as is here reported. 

The studies have been made with vitally important commercial factors 
in a commercial breed. It is especially incumbent on the eastern pro- 
ducer to excel in the production of these desired factors in order to compete 
with more distant production. Therefore the fact indicated by these 
studies, namely, that the characters in question are distinctly inherited, 
should be gratifying and encouraging to commercial poultrymen who 
have been working for years along these lines. 

The inheritance of the characters studied seemed to be thru the medium 
of both the male and the female parent. The writer found no evidence 
of distinctly sex-linked factors, such as were observed by Pearl (1912) 
and by Hadley (1913). According to the writer's results, benefit to the 
flock can be gained for any of these inherited characters by adding either 
better males or better females to the flock. 

The relation of an individual egg to the mean type produced by the 
parent bird, and the relation of the type of egg incubated to the mean 



306 Earl W. Benjamin 

type produced by the progeny, point directly to an easy way of improving 
a commercial flock by careful selection of the eggs for hatching. The 
results of this investigation show that a study of all the eggs produced 
by the parent hen, such as would be possible only by trap-nesting, would 
be more dependable than a selection of the incubated eggs alone; but the 
latter method is found to be a possible way, as well as an easier and quicker 
way, of obtaining good results. 

The fact that the size, the shape, or the color of eggs does not affect their 
incubation record, leaves the poultryman free to select his eggs for hatch- 
ing according to his own preference without its affecting the percentage 
of hatch. 

The old opinion that hens' eggs approach a definite standard, to which 
they adhere more uniformly as the bird becomes older, is not borne out 
by the results of these studies. From this work it seems that the variability 
of a hen's production does not decrease as the hen becomes older. If 
the indication shown here is a fact, it does away with one of the several 
arguments which the poultryman has for using hens' eggs instead of 
pullets' eggs for hatching. The work of Pearl (1909) with Plymouth 
Rocks does not show agreement with this theory. 

There seem to be no gradual and consistent changes thruout the life 
of the bird for any of the three egg characters studied. Nearly all of the 
changes noted occur between the productions of the first and the second 
year. Since the eggs produced during the second year are nearer to the 
mean for the entire life production of a bird kept for from three to four 
years, it would be expected, and was found generally, that the eggs 
selected for incubation produced by hens two years old or older, gave 
more consistent correlations than those produced by pullets. 

The positive relation of the size of the egg incubated to the size of the 
resultant chick and mature bird, is of value to poultrymen who are inter- 
ested in the production of either poultry or eggs. 

The inheritance of the characters studied is undoubtedly of the type 
of a Galton regression. Much further study is needed in order to properly 
analyze the unit factors, or physiological units, involved in the formation 
of the broad practical characters here observed. Until further results 
are available, however, the fact that certain general lines of inheritance 
ars known gives breeders some evidence on which to base more work 
for the improvement of their flocks. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 307 

SUMMARY 

The most important results obtained from the studies reported in this 
paper may be grouped into the following conclusions: 

1. The variability of a bird's production for a certain character does 
not depend on the difference existing between that bird's parents for the 
same character. 

2. Both the male and the female have a distinct and approximately 
equal effect on the type of egg produced by the progeny, but the combined 
effect of the two is much greater and is directly inherited by the progeny, 
as is shown by the type of egg produced. 

3. A mating of two opposite extremes of character always caused the 
production of a medium character in the progeny. 

4. A mating of two similar extremes of character usually caused the 
production of a character approaching normal, in the progeny. 

5. It appears that small size and length of egg are dominant, while 
there seems to be no dominancy whatever for color. 

6. The correlations between the type of egg incubated and the mean 
type produced during the life of the respective progeny, are positive in 
every instance and are significant except for the color character. These 
correlations are not so significant as those between the mean types of 
eggs produced by the parents and the respective progeny. 

7. The color character is much more irregular than the size or the 
shape, and less reliance can be placed on the stability of any color type 
when selecting eggs for hatching. 

8. It does not appear that any more reliance can be placed on the 
stability of the progeny type hatched from hens' eggs than on that hatched 
from pullets' eggs. 

9. The type of egg incubated affects the mean type of egg produced 
during the life of the bird hatched, to a greater extent than it affects 
the pullet-year production or the production of any other single year. 

10. A strong correlation exists between the types of eggs produced by 
individuals and the types of eggs from which these individuals were 
hatched. 

11. There is no correlation between the size and the shape of eggs 
produced by the birds used in this experiment. 

12. The size, the shape, and the color of the egg seem to have no effect 
on its incubation record. 






308 Earl W. Benjamin 

13. No definite tendency is shown toward a reduction of the variability 
of type of eggs produced by individual birds during successive years. 

14. During the pullet year the size of the eggs produced increases 
rapidly, but after the first year's production no appreciable change in 
the size of the eggs produced can be found. 

15. There seems to be no perceptible and consistent difference between 
the shapes of eggs laid by pullets and those laid by hens. 

16. There is a tendency for the eggs produced each year, even in the 
pullet year, to have a gradually increasing index until the fifth or the 
sixth month of production, after which this index gradually decreases 
until the season's production ceases. 

17. The eggs produced by hens two years old or older, are more likely 
to be tinted, or are tinted darker, than the eggs produced by the same birds 
during their pullet year. 

18. There is no gradual darkening of the shell pigment after the second 
year's production. 

19. Each year there is a tendency for the eggs produced to gradually 
become whiter during the first five or six months of production, and then 
to become more tinted again toward the end of the production season. 

20. The data presented show that when eggs are laid by an individual 
bird for two or more successive days, the eggs become successively smaller, 
have a larger index, and are more deeply tinted. 

21. A distinct positive correlation is found between the size of the eggs 
incubated and the vigor of the respective chicks hatched, at various 
ages of the chicks. The correlation is especially significant during the 
period of severe weather conditions. 

22. A constant figure to represent x in the ratio, female weight : male 
weight : : x : 1, was calculated for a part of the available material at 
various ages, and this figure was found to agree closely with Galton's 
constant for human stature of 0.93. 

23. There is a significant positive correlation between the size of the 
eggs incubated and the size of the respective chicks hatched. This 
correlation persists during the life of the birds as far as it was studied; 
that is, during a period of 228 weeks. 

24. All of the eggs produced by any one hen tend to be of a characteristic 
type as to size, shape, and color. 



Study of Selections for Size, Shape, and Color of Hens' Eggs 309 

25. Certain individuals have the power to transmit their characters 
much better than do others. 

26. The results of these studies indicate a condition of inheritance 
resembling a Gal ton regression, for all characters studied. 

ACKNOWLEDGMENTS 

The materials and equipment used for this study were supplied by the 
Department of Poultry Husbandry of the New York State College of 
Agriculture at Cornell University. The writer wishes to express his 
appreciation for these facilities and for the valuable advice furnished by 
Professor James E. Rice, of the Department. The helpful suggestions 
given by Dr. H. H. Love, of the Department of Plant Breeding at Cornell 
University, are also appreciated. 



310 Earl W. Benjamin 



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Memoir 29, The Lecithin Content of Butter and its Possible Relationship to the Fishy Flavor, the second 
preceding number in this series of publications, was mailed on December 23, 1919. 



